We apply the theory to liquids and gases to see how they compare to each other.

We will look at the different types of intermolecular forces. A special type of intermolecular interaction called hydrogen bonding involves hydrogen and other elements.

Two important properties of liquids can be understood in terms of intermolecular forces.

We learn about the nature of crystals and ways of packing spheres to form different unit cells as we move on to the world of solids.

The best way to determine the dimensions of a crystal structure is by X-ray diffraction, which is based on the scattering of X rays by the atoms or molecule in a crystal.

Ionic, covalent, molecular, and metallic are the major types of crystals. Intermolecular forces help us understand their structure and physical properties.

Solids can be found in the form of a lump, which lacks an orderly three-dimensional arrangement. Glass is an example of an amorphous solid.

The equilibrium between liquid and vapor gives rise to equilibrium pressure. Vaporization depends on the strength of intermo lecular forces. Every substance has a critical temperature above which it cannot be liquefied. We look at liquid-solid and solid vapor transitions.

The various types of phase transitions are summarized in a phase diagram, which helps us understand conditions under which a phase is stable and changes in pressure and temperature are needed to bring about a phase transition.

We use water and other liquids every day for drinking, bathing, cleaning, and cooking, and we handle it.

The atoms and molecules are packed tighter together in liquids than in gases. They are held in well-defined positions in a solid and are capable of little free motion relative to one another. We will discuss some of the fundamental properties of liquids and solids in this chapter. We will look at the nature of transitions among gases, liquids, and solids.

The behavior of gases in terms of their constant, random motion was explained in Chapter 5. At ordinary temperatures and pressures, there is no interaction between the molecules because the distances between them are so great. Gases can be compressed because there is a lot of empty space. The lack of strong forces between the molecules allows a gas to expand.

The large amount of empty space explains why gases have low densi ties.

Liquids and Solids are not the same. The distance between mol ecules is the main difference between the two states. There is very little empty space in a liquid because the molecule are so close together.

Under normal conditions, shape much denser with fixed positions. Section 11.2 will discuss the types of attractive forces that hold the Molecules in a liquid together. Molecules in a liquid do not break away from the attrac tive forces. The molecule can move past one another, and so a liquid can flow, can be poured, and assume the shape of its container.

There is no freedom of motion in a solid.

The molecules are arranged in three dimensions in a long-range order. There is less empty space in a liquid than in a solid. Solids have a definite shape and volume.

The density of the solid form is higher than that of the liquid form for most substances. Two states of a substance can coexist. An ice cube floating in a glass of water is a familiar example. The different states of a substance are referred to as phases. The solid and liquid phases of water are contained in our glass of ice water. Changes of state involving one substance, as well as systems containing more than one phase of a substance, will be referred to as "phase" in this chapter. The characteristic properties of the three phases of matter are summarized in Table 11.1.

The nonideal behavior of gases is caused by intermolecular forces. They exert more influence in the Condensed phases of matter.

At a sufficiently low temperature, the molecule no longer has enough en ergy to break away from the attraction of the neighboring molecule. Themolecules aggregate to form small drops of liquid.

Intermolecu lar forces are primarily responsible for the bulk properties of matter, for example, melting and boiling points.

Intermolecular forces are not as strong as intermolecular forces. It takes less energy to evaporate a liquid than to break the bonds in the mole cules of the liquid. It takes about 41 kJ of energy to break the bonds in 1 mole of water, but it takes more than that to break the bonds in 1 mole of water. The strength of the intermolecular forces is reflected in the boiling points of substances.

Liquids and Solids can enter the vapor phase. The boiling point of A is higher than the boiling point of B because A and B are held together by stronger intermolecular forces. The same principle applies to the melting points of the substances. The strength of the intermolecular forces affects the melting points of substances.

Understanding the different types of intermolecular forces is needed to discuss the properties of Condensed Matter. Only a few elements can participate in hydrogen bond formation. More than one type of interaction may contribute to the total attraction between molecule, as we will see in this chapter.

cations are usually smaller than anions and the charges on them are more concentrated.

Section 4.1 discusses hydration as an example of ion-dipole interaction. The heat of hydration is caused by the interaction between the cations and anions of an ionic compound with water.

The Na+ ion interacts with water more strongly than the Mg2+ ion because it has a higher charge.

He and N2 are gases that can be polarizability enabled to condense. The electrons are moving away from the nucleus. The atom is likely to have a dipole moment at any moment. The atom has a new instantaneous dipole when the electrons are in different locations. The atom has no dipole moment because the instantaneous dipoles all cancel one another. In a collection of He atoms, an instantaneous dipole of one He atom can cause a dipole in each of its nearest neighbors. Transient dipoles can be created in the surround ing He atoms at the next moment. dispersion forces and heat of hydration of individual ion can be estimated at very low temperatures.

The dipoles interact with each other. The condensation of nonpolar gases is caused by this type of interaction.

The Intermolecular Forces and Liquids and Solids are strong enough to hold He atoms together. The attrac tion can be explained in similar ways.

In 1930, a quantum mechanical interpretation of temporary dipoles was provided. The magnitude of this attractive interaction is determined by the polarizability of the atom or molecule.

The melting point is expected to increase as the number of electrons in the molecule increases.

The dispersion forces are comparable to or better than the CBr4 90.0 dipole forces.

CI4 171.0 boiling points of CH3F and CCl4. Although CH3F has a dipole mo ment of 1.8 D, it doesn't boil at the same temperature as CCl4.

CCl4 will boil at a higher temperature because it has more electrons.

If we know the type of species present, we can determine the types of intermolecular forces that exist between them.

The species should be categorized into three categories: ionic, polar and nonpolar.

The forces present are intermolecular and dispersion forces.

London was a theoretical physicist who worked on superconductivity.

The forces are not static.

The types of intermolecular forces that exist in each of the following species are LiF, CH4 and SO2.

The boiling points of compounds containing elements in the same periodic group increase with increasing mass. The increase in boiling point is due to the increase in dispersion forces. Group 4A's hydrogen compounds follow the trend shown in Figure 11.6. The lightest compound, CH4, has the lowest boiling point, while the heaviest compound, SnH4, has the highest boiling point. The elements in Groups 5A, 6A, and 7A do not have hydrogen compounds. The lightest compound in each series has the highest boiling point, contrary to our expectations.

H and HF are in the same group.

A and B are part of a molecule and the dotted line shows the hydrogen bond.

The O, N, and F atoms all have a single pair that can interact with the hydrogen atom.

The average strength of a hydrogen bond is large. hydrogen bonds have a powerful effect on the properties of many compounds.

The strength of a hydrogen bond is determined by the interaction between the hydrogen nucleus and the lone-pair electrons. We would expect a stron ger hydrogen bond to exist in liquid H2O because of the fact that fluorine is more negative than positive.

The forces holding the molecule together are stronger in H2O. Section 11.3 contains the important property of water.

A species can form hydrogen bonds with water if it has a H atom that bonds to one of the three elements.

There are no negative elements in either CH4 or Na+.

Only CH3OCH3, F-, and HCOOH can form hydrogen bonds with water.

HCOOH can form hydrogen bonds with water in two different ways.

The intermolecular forces are attractive in nature. Molecules exert repulsive forces on one another. The repulsion between the electrons and the nuclei in the molecule comes into play when two molecules approach each other. The repulsive force increases as the distance between the molecules decreases.

Liquids are hard to compress. The molecule are already in contact with one another, so they resist being compressed further.

In this section, we will look at two phenomena associated with liquids. The structure and properties of water will be discussed.

Molecules within a liquid are pulled in all directions by intermolecular forces. The molecule at the surface is pulled downward and sideways by other molecule, but not upward away from the surface.

A sphere reduces the surface area of a liquid. A wet apple has a waxy surface.

The surface tension is the measure of the elastic force on the liquid's surface. Liquids with strong intermolecular forces have high surface tensions. Water has a higher surface tension than most other liquids.

Figure 11.10(a) shows a capillary tube. The water's surface tension causes the film to contract and pull the water up the tube. capillary action is brought about by two types of forces.

Once the weight of the water in the tube is balanced, this process will stop. Figure 11.10(b) shows that this action is not universal among liquids. When a capillary tube is dipped in mercury, the result is a depression or lowering, because the height of the liquid in the capillary tube is below the surface of the mercury.

The expression "slow as molasses in January" is based on the fact that the liquid's viscosity is related to the expression.

The slower the liquid flows, the greater the viscosity is. As temperature increases, hot molasses flows faster than cold molasses.

Liquids with strong intermolecular forces have higher viscosities than those with weak intermolecular forces. Water's ability to form hydrogen bonds makes it a higher viscosity liquid. The viscosity of glycerol is higher than that of all the other liquids.

Professor Parnell wanted to show his physics students the de rivative of tar, a property of pitch. The viscoelastic nature of pitch means that it will break into pieces if struck with enough force, but it also flows slowly.

Parnell heated a sample of pitch to a temperature that he lowed it to be poured into a funnel, and the funnel and receiving beaker were covered with a bell jar and placed on display outside of the lecture hall.

The first drop fell after the pitch settled in the funnel and the stem was cut, but no one saw it fall. It took roughly one drop per decade for the drops to fall. After the third drop fell, Professor John Mainstone took over as guardian of the experiment, but he did not get to see any of the five drops that fell during his 52 years as curator, including several near misses and a webcam failure.

John was watching the experiment.

The SI units of the water are newton-second per meter squared.

Hydrogen bonds can be formed by glycerol. There are three groups of glycerol molecule that can bond with each other. Because of their shape, the molecule have a tendency to become entangled rather than to slip past one another. The interac tions contribute to its high viscosity.

We often overlook the unique nature of water because it is so common.

Water is involved in all life processes.

Table 6.2 shows that water has a high specific heat. We must first break the many intermolecular hydrogen bonds to raise the temperature of water. It is possible for water to absorb a lot of heat while its temperature remains the same. Water can give off a lot of heat with a small decrease in temperature. It is possible to moderate the climate of adjacent land areas by absorbing heat in the summer and giving off heat in the winter, with only small changes in the temperature of the body of water.

Ice floats at the surface of liquid water, which is the most striking property of water. The density of most substances is greater in the solid state than in the liquid state.

We have to look at the electronic structure of the H2O molecule to understand why water is different.

Water is joined together in an extensive three-dimensional network in which each oxygen atom is approximately tetrahedrally bonding to four hydrogen atoms, two by covalent bonds and two by hydrogen bonds.

The number of hydrogen atoms and lone pairs is not characteristic of NH3 or any other molecule capable of forming hydrogen bonds. The other molecule can form rings or chains, but not three-dimensional structures.

The three-dimensional structure of ice prevents the molecule from getting too close to one another. When ice is melted, what happens? There is enough energy in the water to break free of the hydrogen bonds. These molecules are trapped in the three-dimensional structure and are broken down into smaller clusters.

In a cold climate, tempera ture changes in the fresh water of a lake. The density of the water increases when the temperature drops. The warmer water rises to the top while the colder water sinks to the bottom. The motion continues until the temperature in the water reaches 4 degrees. The water starts to freeze at the sur face. The ice layer doesn't sink because it is less dense than the liquid, and it acts as a thermal insulation for the water below it. The ice would sink to the bottom of the lake if it was heavier. The organisms in the water could not survive in ice. Lake water doesn't freeze up from the bottom. The water makes ice fishing possible.

The ice layer on the surface of the lake insulates the water beneath and maintains a high enough temperature to sustain aquatic life.

Four H atoms are bonded to the O atom.

There are more molecules in liquid water than in ice. The density of water is greater than that of ice. The density of water tends to increase with rising temperature just above the melting point because more water is released from intermolecular hydrogen bond g/ 0.99 ing.

The density is decreased. The trap 0.97-20 0 20 40 60 80 ping prevails and water becomes denser.

Solids can be categorized into two categories. The net attractive intermolecular forces are at their maximum because of the arrangement of such particles. ionic forces, covalent bonds, van der Waals forces, hydrogen bonds, or a combination of these forces are responsible for the stability of a crystal. They will be discussed in Section 11.7. In this section, we will look at the structure.

The lattice point of many crystals does not contain a particle. There may be several atoms, ion, and molecule identically arranged about each lattice point. We can assume that each lattice point is occupied by an atom. This is the case with most metals. All sides and all angles are equal in the geometry of the unit cell. The lattice structure is formed when the unit cells are repeated in space in all three dimensions.

What type of unit cell we have is determined by the way the spheres are ranged.

The three-dimensional structure can be created by placing a layer above and below it in a way that spheres in one layer are over the others. In the case of a crystal, this procedure can be extended to generate many layers. There are four spheres in its own layer, one in the layer above, and one in the layer below. The larger the coor dination number, the closer the spheres are to each other.

Each sphere in this structure has a coordination number of eight, with four in the layer above and four in the layer below.

Most of a cell's atoms are shared by neighboring cells because every unit cell is adjacent to other unit cells. The edge atom is shared by four unit cells and the face-centered atom is shared by two unit cells. The equivalent of two complete spheres, one in the center and eight shared corner spheres, can be found in a body-centered cubic cell.

A face-centered cell has three face centered atoms and one corner sphere.

The face-centered cubic cell has more empty space than the simple and body-centered ones.

In the second layer, spheres are packed into the depres sions between the spheres in the first layer so that they are as close together as possible.

There are two ways that a third-layer sphere can cover the second layer. The spheres may fit into the depressions so that they are over the first-layer sphere. We call the third layer layer A because there is no difference between the first and third layers. Each sphere has a coordina tion number of 12 and is in contact with six other spheres in its own layer, three other spheres in the layer above, and three other spheres in the layer below. There is no way to increase the coordination number beyond 12 because the hcp and ccp structures are the most efficient way of packing identical spheres in a unit cell.

Many metals and noble gases form crystals. Magnesium, titanium, and zinc have their atoms in a hcp array, while aluminum, nickel, and silver have their atoms in theccp arrangement. The ccp structure of noble gases is the only structure that is different from the hcp structure. It's natural to ask why a series of related substances would form different crystal structures.

The hcp structure of magnesium metal results in the greatest stability of the solid.

If the den sity of the crystal is known, this relationship can be used to determine the atomic radius of a sphere.

The face-centered cubic unit cell has a density of 19.3 g/ cm3.

We want to know the radius of a gold atom. The density in the problem is given to us.

In order to determine the volume, we have to find the mass of the unit cell. There are eight corners and six faces in each unit cell.

The face-centered cubic cells are formed when silver becomes face-centered. The edge length of the unit cell is 408.7.

The W atoms occupy only the lattice points.

Cerium forms face-centered cells.

Most of the information about crystal structure has been learned from X-ray studies. The arrange ment of particles in the solid lattice is deduced by the scattering.

Because X rays are one form of radia tion, we would expect them to exhibit such behavior. An X-ray pattern is the result of interference in the waves.

The figure shows a typical X-ray setup. A mounted crystal has a beam of X rays directed at it.

Von Laue won the physics prize in 1914 for his discovery of X-ray diffraction.

Consider the scattering of X rays by atoms in two parallel planes to understand how a pattern may be created.

The lower wave is reflected by an atom in the first layer, while the upper wave is reflected by an atom in the second layer.

The example shows the use of Equation.

The aluminum crystal is reflected by the X rays at an angle of 19.3deg. The angle of reflection is caused by the spacing between the planes of aluminum atoms. The conversion factor is obtained from 1000 pm.

This is an example of an equation.

Bragg worked in X-ray crystallography.

His son Sir William Bragg won the physics prize in 1915.

Bragg and his father shared the physics prize in 1915.

The X rays of wavelength 0.154 are diffracted from a crystal. The distance between layers in the crystal can be calculated.

The most accurate method for determining bond lengths and bond angles is the X-ray diffraction technique. Because X rays are scat tered by electrons, chemists can use a complex mathematical procedure to create an electron-density map. The densities are close to the center of the atom. The positions of the nuclei and the geometric parameters of the molecule can be determined in this man ner.

The X rays of wavelength 0.154 are diffracted from a solid.

The structures and properties of crystals are determined by the forces that hold the particles together. There are four types of crystal: ionic, covalent, molecular, and metallic.

The charged species and anions and cations of ion crystals are different. The structure and stability of these com pounds can be understood with the knowledge of the radii of the ion. Sometimes it is possible to come up with a reasonable estimate, even though there is no way to measure the radius of an individual ion.

The smaller sphere is what the cation is.

The difference between the two values tells us that the ion's radius varies from compound to compound.

The crystal structures of three ionic compounds are shown in Figure. The simple lattice of Cs+ is larger than Na+. The Zn2+ ion is located one-fourth of the distance along each body diagonal if the S2 ion occupies the lattice points. CuCl, BeS, CdS, and HgS are some of the ionic compounds that have the zincblende structure.

The number of ion in and density of a unit cell are shown in examples.

A face-centered lattice is the basis of the structure. One whole Na+ ion is at the center of the unit cell, and there are twelve Na+ ion at the edges. At the face centers there are six and at the corners there are eight. There are four Na+ ion and four Cl- ion in each NaCl unit cell.

The result agrees with the formula.

Up to 20 percent of electrical energy may be too hot to transmit, and would far exceed the heat lost in the form of heat when cables made of these metals are used.

Although 30 K is still a very low temperature, the improvement metals and alloys, when cooled to very low temperatures over the 4-K range was so dramatic that their work lost steam.

The NaCl unit cell has an edge length of 888-276-5932 888-276-5932 888-276-5932 888-276-5932.

We need to know the mass of the unit cell to calculate density.

We can see that there are four Na+ ion and four Cl- ion in each cell.

First is an inexpensive compound with a mixed oxide of yttrium, barium, and large quantities are available for testing. The photo shows a magnet being levitated above a supercon metal alloy superconductors at 4 K.

It is hoped that someday superconductors will live up to their promise. After 30 years of intense research and development, scientists will be able to build supercomputers, whose speeds are limited by still puzzle over how and why these compounds superconduct.

magnesium diboride becomes perconducting at 40 K. It is cheaper to use 27 K as a coolant than it is to use liquid nitrogen.

The Cu atoms are at the lattice points only.

The higher the lattice energy, the more stable the compound is.

The ion are fixed in position and do not conduct electricity. In the molten state, the ion can move and the resulting liquid is conducting.

In a three-dimensional net work, atoms are held together by bonds.

It is three- hybridized and bonds to four other atoms.

Carbon atoms are arranged in six-membered rings. Each atom has a bond with three other atoms. The kind of delocalized mo lecular orbital that is present in benzene is present in each layer of graphite. electrons are free to move around in this extensively delocalized molecular orbital, so it is a good conductor of electricity in directions along the planes of carbon atoms. Weak van der Waals forces hold the layers together. Because the layers can slide over one another, graph ite is slippery to the touch and is effective as a lubricant. It is also used in printers.

The crystal is SiO2. There is an oxygen atom between each pair of Si atoms in quartz. The SiO bond is polar because Si and O have different electronegativities. SiO2 is similar to diamond in many ways.

The attractive forces between the lattice points are van der Waals forces and hydrogen bonding. Solid sulfur dioxide is an example of a crystal in which the attractive force is a dipole-dipole interaction. I2, P4, and S8 are some of the ex amples of crystals.

As their size and shape allow, the molecules in the crystals are packed together closely.

The periodic table shows the positions of the metals.

Most crystals melt at temperatures below 100degC.

Every lattice point in a metallic crystal is occupied by an atom of the same metal.

The metallic elements are usually very dense.

The bonding in metals is different than in other types of crystals. The bonding electrons are delocalized in a metal.

All metallic elements are good conductors of heat and electricity.

A good thermal conductor is diamond.

White tin is stable at room temperature and above.

It slowly becomes gray tin. The microcrystals of gray tin are random and make the metal fall apart. In the Russian winter, the soldiers were more focused on holding their coats together with their hands than on carrying weapons.

The "tin disease" has been known for a long time. The allo tropic transition from white tin to gray tin caused organ pipes made of tin to fall apart.

The zinc oxide unit cell is shown.

Solids are very stable. If a solid is formed quickly, its atoms or molecules don't have time to align themselves and may become locked in positions other than those of a regular crys tal. The properties of glass will be briefly discussed in this section.

One of the most valuable and versatile materials is glass. It is one of the oldest glass articles in existence. The glass is formed by mixing molten Silicon dioxide (SiO2), its chief component, with compounds such as sodium oxide (Na2O), Boron oxide (B2O3), and certain transition metal oxides for color and other properties. Glass behaves more like a liquid than a solid. Glass lacks long-range periodic order according to X-ray studies.

It is used in optical research.

Small amount of household cooking glassware is used.

Chemicals and sensitive to thermal shocks are easy to attack.

Transmits visible light, but absorbs UV radiation.

CaO is used in bottles and windows.

There are hundreds of different types of glass. The table shows the composition and properties of glass.

The color of glass is due to the presence of metal oxides. For ex ample, green glass contains iron(III) oxide, Fe2O3 or copper(II) oxide, CuO; yellow glass contains UO; and blue glass contains CoO and CuO. Most of the ion are derived from the transition metals.

The discussion in Chapter 5 gave us an overview of the prop erties of the three phases of matter: gas, liquid, and solid. Molecules in the solid phase have the greatest order, while those in the gas phase have the greatest randomness. The relationship between energy change and the increase or decrease in order will help us understand the nature of these physical changes.

Molecules in a liquid are not fixed. Although they don't have the full free dom, they are in constant motion. The liquid phase of the molecule has a higher collision rate than the gas phase. A phase change occurs when the molecule in the liquid has enough energy to leave the surface.

The higher the temperature, the more the molecule leave the liquid.

Vapor pressure is created when a liquid evaporates.

The U-shaped manometer tube has equal mercury levels before the process starts. A vapor phase is established when some molecule leave the liquid. When a fair amount of vapor is present, the vapor pressure is measurable. The process of evaporation isn't done indefinitely. There are no further changes in the mercury levels.

Molecules are moving from the liquid to the empty space in the beginning. The space above the liquid has a vapor phase.

The rate of con densation increases with the concentration of molecules in the vapor phase, and the rate of evaporation is constant at any given temperature.

When we talk about the equi librium vapor pressure of a liquid, we often use the term "vapor pressure".

The vapor pressure of a liquid is expected to increase with temperature.

The strength of intermolecular forces in the liquid is related to the molar heat of vaporization.

Student data shows you may struggle with pressure. Clausius mainly worked on electricity and resources.

Clapeyron made contributions to the steam engines.

The method is used to determine the temperature of vaporization.

The example shows the use of Equation.

Diethyl ether is a highly volatile organic liquid that is used as a solvent. The vapor pressure of diethyl ether is over 400mmHg.

We are given diethyl ether at one temperature and asked to find the pressure at another. We need Equation.

The higher the temperature, the greater the vapor pressure will be. The answer is reasonable.

The pressure of the liquid is 100mmHg.

You can demonstrate the heat of vaporization by rubbing alcohol on your hands. Your hands feel cooler because of the loss of heat. The human body maintains a constant temperature by perspiration. A lot of energy is needed to evaporate the water from the body's surface because of the strong intermolecular hydrogen bonding. The heat generated in met abolic processes provides this energy.

The vapor pressure of a liquid increases with tempera ture. The temperature at which a liquid begins to boil.

There are bubbles in the liquid at the boiling point. The level of the liquid in the container is forced to rise when a bubble forms.

The bubble rises to the surface of the liquid when the vapor pressure is equal to the external pressure. The bubble would collapse if the pressure in it was less than the pressure outside. The boiling point of a liquid depends on external pressure.

If the pressure is reduced to less than 0.5 atm, the water will boil at less than 100degC.

Our predic tion is confirmed by the data in Table 11.6. Low boiling points and small molar heats of vaporization are what methane andAr have.

The student data shows that Benzene has a high polarizability due to the distribution of its electrons in the delocalized pi orbitals. Your eBook can be as strong as or stronger than the dipole-dipole Resources on this topic.

condensation is the opposite of evaporation. One of two techniques can be used to make a gasliquefy. By cooling a sample of gas, we decrease the energy of the Molecules so that they aggregate to form small drops of liquid. Pressure can be applied to the gas. Compression reduces the age distance between molecule so that they are held together.

liquefaction processes combine two methods.

There is no difference between a liquid and a gas above the critical temperature. The critical temperature can be explained as follows.

The table lists the critical temperatures and critical pressures of substances. The strength of the intermolecular forces is reflected in the critical temperature of a substance. The table shows the critical temperatures of the different sub stances, and Benzene, ethanol, mercury, and water have high critical temperatures.

The process of melting is referred to as fusion.

When the pressure is at 1 atm, the word "normal" is usually omitted.

Water and ice are the most familiar liquid-solid equilibrium.

A glass of ice water is used to illustrate the dynamic equilibrium.

Some of the water between ice cubes may freeze as the ice cubes melt to form water. All the ice cubes will eventually melt away because the glass is not kept at a high temperature.

The temperature of a substance changes when it absorbs heat from its surroundings. As a solid is heated, its temperature increases until it reaches its melting point. The mole cules have become sufficiently large to begin overcoming the intermolecular forces that hold them together in the solid state. A transition from the solid to liquid phase begins in which the absorption of heat is used to break apart the mol ecules in the solid. The temperature stays the same because the age of the molecule doesn't change.

The absorbed heat is used to break the intermolecular forces holding the molecule in the liquid phase so the temperature remains constant. The temperature of the gas increases once this transition has been completed.

The table shows the molar heats of fusion.

This is consistent with the fact that the molecules in a liquid are tightly packed together, so that some energy is needed to move them from solid to liquid. On the other hand, when a liquid is evaporates, it becomes completely separated from one another and more en ergy is required to overcome the attractive force.

The temperature of a gas sample will decrease if we remove heat at a steady rate. The system gives off heat when the liquid is being formed. The temperature of the liquid begins to drop after all the vapor has evaporated.

When heat is removed from a liquid so quickly that the molecule can't see the ordered structure of a solid, supercooling occurs. Adding a small seed crystal to a supercooled liquid will cause it to solidify quickly.

Vapor quickly entered an enclosed space. Iodine does the same thing. The violet color of iodine vapor can be seen in a closed container.

The vapor pressure of a solid is usually less than that of the corresponding liquid, because themolecules are more tightly held in a solid.

The equation is an example of the law.

The equation can only be used as an approximation if not.

The types of phase changes discussed in this section are summarized in Figure 11.39

When a substance is heated, its temperature will rise and eventually it will undergo a phase transition. We have to calculate the total energy change for that process.

The amount of energy needed to heat 346 g of liquid water is calculated. The specific heat of water is 4.184 J/g * degC over the entire liquid range and the specific heat of steam is 1.99 J/g * degC.

There are three steps to the calculation.

More heat is absorbed during the transition.

The slopes are -2.32 x 103 K and -4.50 x 103 K.

The vapor pressure is 92.47mmHg.

The phase diagrams of water and carbon dioxide will be briefly discussed in this section.

Figure 11.40(b) shows the boiling point and freezing point when ice decreases with increasing external pressure. The phenomenon helps to make ice skating point of water deviate from 100 and 0 degrees. skates have very thin runners, a 130-lb person, as we see in the following discussion.

Suppose you have just scaled a peak in Colorado, and the ice under you is very cold. To help the skates melt and the film of water formed under the run regain your strength following the strenuous work, you decide ner facilitates the movement of the skater over ice.

The melting point of ice decreases by boil more quickly than usual, but after 10 min in boiling water, 7.4 x 10-3 degC when the pressure increases. The egg is not cooked. If you knew phase equilib, you could have avoided the disappointment of cracking open the melting point when the skater is 500 atm.

It turns out that the blades and the with you have something in common. The summit of Pike's Peak is the main cause of ice melting. This explains the level. It is not possible to skate outdoors at this altitude because of the atmospheric pressure. The boiling point of the drops is shown in Figure 11.40(b).

The amount of heat delivered to the egg is proportional to the temperature of the water. It would take 30 minutes to hard-boil your egg.

Pres sure cookers save time in the kitchen because of the effect of pressure on boiling point. A pressure cooker is a sealed container that allows steam to escape. The pressure in the cooker is the sum of the atmospheric pressure and the steam pressure. The food in the pressure cooker will be hotter and the water in it will boil at a higher temperature.

Let's look at the ice-water equilibrium.

Crystalline ice and cules in nematic liquid crystals are not separated into layers because they are aligned with long axes of liquid water.

One class of substances tends so much that they have many applications in toward an ordered arrangement. The transparent aligning agents change into a clear liquid that is made of tin oxide and behaves like an ordinary liquid.

The Molecules that exhibit liquid crystallinity are usually long way. Ther phase is an important class of liquid crystals. When properly adjusted, this twist rotates the plane of motropic liquid crystals, which form when the solid is heated.

The polarizers are arranged at 90 degrees to each other. In smectic liquid crystals, the long axes of field are applied and the nematic molecule experience a Torque. The substance of the field can be slid over by the layers that are free to slide over each other.

A liquid crystal display. There are Molecules in contact with the bottom and top cell surfaces. The cell appears clear.

Under the bottom polarizer is where a mirror can be placed in watches and calculators. In metallurgy, the reflected light goes through both polarizers and is used to detect metal stress, heat sources, and conduction cell. The electric field turns into paths. Liquid crystals can be used to determine the temperature of the body at specific sites. The cell becomes dark when this tech tom polarizer is used.

A thin film in the ms range is the temperature in the affected tissues when the electric field is turned on and off.

cho or tumor is a type of thermotropic liquid crystals that respond to a temperature difference.

The smectic liquid crystals are like a two-dimensional solid.

The highest and lowest temperature are represented by the red and blue colors.

The diagram of water is shown in Figure 11.40(a).

The other two curves show equilibrium between ice and liquid water and between ice and water vapor. This is the point for water.

Phase diagrams allow us to predict changes in the melting and boiling points of a substance as a result of changes in the external pressure; we can also anticipate phase transitions brought about by changes in temperature and pressure. The boiling point of water at 1 atm is 100degC. The boiling point will be lowered and the melting point raised by a decrease in pressure.

This holds true for most substances. There is a triple point of carbon dioxide.

Student data shows that it is not possible for solid carbon dioxide to melt at 1am because the liquid phase lies well above atmospheric pressure. Solid CO2 has trouble with phase diagrams.

Dry ice can be used as a refrigerant.

Define the different types of intermolecular forces: dipole-dipole, hydrogen bonding, dispersion forces, and ion-dipole. Evaluate the forces present in the substance. The atomic radius of an atom is determined by its density and crystal type. The Bragg equation can be applied to the X rays. The major types of crystals are ionic, covalent, molecular, and metal ic.

Liquid-vapor, liquid-solid, and solid-vapor are the major types of phase equilibria. The Clausius-Clapeyron equation can be used to calculate the vapor pressure of a liquid. Phase diagrams can be used to identify the triple point and determine the phase of a substance at a given temperature and pressure.

There are three states in which substances exist: gas, liquid, and small solid.

A regular struc 2 is used for all of the solids. Intermolecular forces act between atoms or be ture of atoms. These are usually attractive out of a regular structure. Glass is an example of a weak force.

A three-dimensional cules or ions can be formed by repeating the unit molecule with dipole moments to another polar mole cell.

Our knowledge about crystal structure causes dispersion forces.

The polarizability is the extent to which a dipole moment can be created in particles together. The term "van ionic bonding; covalent crystals, covalent bonding; mo der Waals forces" refers to dipole-dipole, dipole- lecular crystals, and van der Waals forces.

A liquid in a closed vessel eventually establishes an interaction between a polar bond containing a hydro namic equilibrium between the condensa Gen atom and the O, N, or F atom.

The equilibrium vapor pressure, which is larly strong, is the result of the hydrogen bonds between the water and the liquid.

Liquids assume a geometry that is smaller. The external pressure is equal to the surface tension. The strength of intermolecular forces in a liquid leads to greater surface tension.

A measure of the resistance of a liquid to the vapor pressure of the liquid is called Viscosity.

The energy required to melt one mole of the solid is the molar heat of fusion.

Every substance has a temperature that is called the Gen-bonded to two hydrogen atoms. The critical temperature above which the gas phase cannot ture accounts for the fact that ice is less dense than be made to liquefy.

Water is ideally suited for its ecological role due to its region being a pure phase and the boundaries being high specific heat. There are large bodies of water where the two phases are in equilibrium. All three phases are in equilibrium at the triple able to moderate Earth's climate.

Both of these compounds have the same number of atoms.

NH3 or PH3 is what LiF is.

Give some evidence that atoms and Molecules exert attractive forces on one another.

The compounds have the same number of electrons, but they melt at different temperatures.

The boiling points increase from CH4 to SnH4.

Ammonia is a donor and acceptor of hydrogen.

Despite the fact that water is denser than steel, a razor blade can be made to float on water.

The metal in the glass is 3.50 g/ cm3. This information is being used.

Draw diagrams show the capillary action of the volume in cm3 with water and mercury in three different tubes.

The V atoms occupy only the lattice points, so why does the liquid's viscosity decrease?

Outside water pipes have to be drained or insulated because the Eu atoms occupy only the lattice points.

The density of Eu is close to 5 g/ cm3.

The Crystalline Silicon has a structure. Predict which of the following liquids has the longest cell edge. The solid surface tension has a density of 2.33 g/ cm3.

There are 8 X atoms in a face-centered cell.

The table shows the distance between layers. The X rays are diffracted at boiling points.

The melting points of the oxides of the third-period wavelength of the X rays are calculated.

The ability of a metal to conduct spheres is the same.

The 11.51 A solid is hard, brittle, and nonconducting.

The unit cell has a substance con edge length. The iron density is 7.87 g/kWh.

The Ba atoms are only at the lattice points of the solid, melt, and solution.

The edge length of the unit cell is 502 pm.

A solid is very hard and has a high melting point.

The solid and melt don't conduct electricity.

A beaker of water is heated to boiling by a Bunsen as ionic crystals, covalent crystals, and molecular crys burner.

Explain why diamond is harder.

Define glass because how is the rate of evaporation of a liquid affected.

Estimate the heat of the liquid.

The compounds listed with their boiling that can occur among the vapor, liquid, and solid points are liquid.

Use any one of the phases to explain what coffee is and then remove the ice component with a meant by dynamic equilibrium.

The clothes are found to be fairly dry after a few hours.

The drying process has phase changes.

There are more serious burns caused by steam at 100degC.

The greater the molar heat of vaporization of a liq temperatures, the more mercury is shown.

What is the boiling point of mercury?

The vapor pressure of benzene, C6H6, is 40.1mmHg. The ture is rising. The boiling point molar heat of benzene is 31.0 kJ/mol.

The vapor pressure of liquid X is lower than that of the liquid, so there is no need for a further rise in temperature.

Explain why splashing a small amount of liquid ni forces in a liquid and the liquid's boiling point is necessary. The critical temperature is boiling water on your skin.

The following properties are indicative of most substances.

The phase diagram of sulfur is shown.

Determine the stable 1288 atm phase of CO2 at 4 atm and -60degC and -20degC.

Classify the unit cell.

A block of ice has a length of wire on top of it.

A heavy weight is attached to each end of the wire as it extends over the edges of the ice. The ice under the wire slowly melts, so that the wire slowly moves through the ice block.

There is a fire extinguisher on the outside of the phenomenon.

The boiling point and freezing point of sulfur diox months can be heard in the winter.

When it is shaken, the triple point is not a sound.

Draw a rough sketch of the has not been used if you assume that the extinguisher has no leaks.

The normal pressure of mercury is 2.

Predict what would happen when a flask of water is connected to a powerful vacuum pen. We raise the temperature at constant pressure when the pump is turned on.

After a few minutes, the same water begins to freeze.

Any substance's liquid-vapor boundary line stops abruptly at a certain point.

Which has a higher density of SiO2 or d.

The south pole of Mars is covered in dry ice. During the summer, false boost can be achieved. The heat of the sublima composition caused the CO2 to evaporate when the tempera added the milk. The atmospheric pressure on the surface of Mars is determined by the pre tion of CO2 that is 25.9 kJ/mol. The re fig ure 11.41 was used to determine the normal sublimation sulting stonelike particles, which caused severe dehydration and damage to many babies.

There are differences in the properties of gases, liquids, and solids.

The substance in each pair should have a higher boiling point. The vapor pressure of a liquid in a closed container depends on which of the following:

A student is given four solid samples labeled W, X, Y, and molecule, which tend to avoid contact with and Z. Z has a metallic luster.

Poor electrical conductors are Y and Z.

There is no effect on W, Y, or Z.

The standard enthalpy of formation of gaseous mo can be identified by the test results.

Match the lines with the compounds.

The kettle of boiling water is on the stove. The phases in regions A and B are identified.

The steam has a specific heat of 1.99 J/g.

Determine the number of LiCl and 203 pm in a LiCl unit in the gas phase.

The bond lengths are different.

The heat change that occurs when the ion becomes hydrated in solution is called the num. A test for ozone is based on ion-dipole interactions. When exposed to ozone, the hydration for the alkali metal ion are Li+, -520 kJ/cury, Na+, -405 kJ/mol, and K+, -321 kJ/mol.

There is a trend in these values.

Table 9.4 shows the rity atom for every Si atom.

The advantages of using 350degC to form gaseous trichlorosilane are explained based on intermolecular purities.

A beaker of water is placed in a container.

The phase diagram of helium is shown. There are eight Si atoms. The only known substance that has two different liqs is 1.0 x 1013.

A sample of water is injected into a evacu Vapor ated flask.

Liquid by the spheres.

A drop of liquid nitrogen can be prepared by swimming coaches.

Use the concept of intermolecular forces to explain why the far end of a walking cane rises.

The compound dichlorodifluoromethane (CCl2F2) has a boiling point of -30degC, a critical temperature of 112degC, and a critical pressure of 40 atm. The atomic radius should be based on a graphical interpretation.

A student heated a beaker of cold water.

A chemistry instructor noticed that there was water on the out mystery demonstration.

She removed the flask from the floor. How would you show from the flame and close the flask with a rubber? In front of the students, the pressure is at 1 atm flask and she announced it throughout the process. The curves don't need to be touched to make the water boil.

Iron is in a lattice.

The length of the cell is determined by X-ray diffraction.

Avogadro's number is given in the phase diagram of carbon.

There is a Appendix diamond that can be made from graphite.

The scales for all the graphs are the same and 0.171 cm is vaporized in a 0.843-L container.

The pressure is 19.2mmHg. The density and atomic radius are used to identify the metal.

The density of gaseous HF should be calculated at its normal boiling point.

The density that was measured was 3.10 g/L.

The graphs show the amount of crepancy between your calculated value and the ex heat transferred to it.

Both calcium and strontium can be seen on a summer day.

The long-range order curve should not be labeled CH3OH. The results are in a liquid.