Properties of Matter
For water, the transition from liquid to solid occurs at _______ .
0°C The water could then be cooled to 0°C, at which point continued cooling would freeze the water to ice.
The standard pressure for measuring boiling points is
760 mm Hg The normal boiling point of a liquid is the temperature at which the vapor pressure of the liquid is equal to the standard atmospheric pressure of 760 mmHg.
In the four settings below, the boiling point of water is highest at
Death Valley, California (282 feet below sea level)
A given liquid will evaporate less quickly when it is heated.
False A given liquid will evaporate more quickly when it is heated.
A liquid whose particles have higher kinetic energies will evaporate more slowly than a liquid whose particles have a lower kinetic energy.
False A given liquid will evaporate more quickly when it is heated.
Absolute zero has been reached in the laboratory.
False Absolute zero has never been attained in the laboratory, but temperatures on the order of 1 × 10−10 K have been achieved.
At the boiling point, the temperature will continue to increase as the liquid water changes into steam.
False As with the previous state change, the temperature will remain steady at 100°C while the intermolecular hydrogen bonds are being broken and water molecules pass from the liquid to the gas state.
Collisions between gas molecules result in loss of kinetic energy.
False Collisions between gas particles and between particles and the container walls are elastic collisions. An elastic collision is one in which there is no overall loss of kinetic energy. Kinetic energy may be transferred from one particle to another during an elastic collision, but there is no change in the total energy of the colliding particles.
The transition from liquid to vapor is called condensation.
False Condensation is the opposite of vaporization. Liquids vaporize to become gases (vapor).
Evaporation of a liquid does not occur below the boiling point.
False Evaporation is the conversion of a liquid to its vapor form below the boiling temperature of the liquid
Stirring a solute affects the overall amount dissolved.
False It is important to realize that neither stirring nor breaking up a solute affect the overall amount of solute that dissolves. It only affects the rate of dissolving.
Metallic crystals are poor conductors of electricity.
False Metals are good conductors of electricity.
Carbon dioxide only transitions from solid to liquid.
False One exception to this exact form for a heating curve would be for a substance such as carbon dioxide, which sublimes rather than melts at standard pressure.
A liquid has a defined shape.
False One way in which liquids and gases are similar is that they are both fluids. A fluid is a substance that is capable of flowing from one place to another and takes the shape of its container.
Recrystallization from a supersaturated solution is very slow.
False Recrystallization from a supersaturated solution is typically very fast.
The temperature dependence of vapor pressure for a liquid is linear.
False The boiling points of various liquids can be illustrated by vapor pressure curves. A vapor pressure curve is a graph of vapor pressure as a function of temperature
The mmHg is the standard unit of pressure.
False The pascal (Pa) is the standard unit of pressure.
A greater surface area decreases the amount of material dissolved.
False The rate at which a solute dissolves depends upon the size of the solute particles. Dissolving is a surface phenomenon, since it depends on solvent molecules colliding with the outer surface of the solute. A given quantity of solute dissolves faster when it is ground into small particles than if it is in the form of a large chunk, because more surface is exposed.
The kinetic-molecular theory only applies to gases.
False The theory helps explain observable properties and behaviors of solids, liquids, and gases.
Particles of a solid crystal are either ions or molecules.
False There are four types of crystals: (1) ionic, (2) metallic, (3) covalent network, and (4) molecular.
Pressure equals
Force/Area Pressure is defined as the force per unit area on a surface.
One of the following does not undergo sublimation
Gold nuggets Sublimation is the change of state from a solid to a gas without passing through the liquid state.
Would you be able to brew a decent cup of coffee on top of Mt. Everest? Explain
Probably not. The boiling point of water is only 70°C at that altitude and the coffee might not be very strong.
One of the following is not a crystal system
Pyramidal The seven basic crystal systems are cubic tetragonal, orthorhombic, monoclinic, rhombohedral, triclinic, and hexagonal.
Only one of the following solids is an example of a covalent network crystal
SiO2 See Table called Crystalline Solids
Review crystal system shapes
Tetragonal a = b ≠ c; α = β = γ = 90° Triclinic a ≠ b ≠ c; α ≠ β ≠ γ ≠ 90° Hexagonal a = b ≠ c; α = β = 90°, γ = 120°
When solid water melts, energy must be put into the system until that process is complete. Why does the temperature remain constant during this process even though additional energy is being added?
The additional energy that might increase the temperature of individual molecules is used to convert more solid to liquid.
How does the average kinetic energy of an air sample near a campfire compare to air that is far away from it?
The kinetic energy is greater near the campfire.
At 373.99°C, particles of water in the gas phase are moving very, very rapidly. At any temperature higher than that, the gas phase cannot be made to liquefy, no matter how much pressure is applied to the gas. Why can't water condense at temperatures higher than this?
The kinetic energy of the molecules at temperatures above the stated one is too high to allow any intermolecular interaction among the molecules.
Some dissolved ions can recombine with the crystal.
True
Vibrational forces disrupt attractive forces at melting point.
True
A crystal is a unit cell repeated over and over again in three dimensions.
True A crystal can be thought of as the same unit cell repeated over and over in three dimensions.
Evangelsista Torricelli invented the barometer.
True An equivalent unit to the mmHg is called the torr, in honor of the inventor of the barometer, Evangelista Torricelli.
An ideal gas is an imaginary gas.
True An ideal gas is an imaginary gas whose behavior perfectly fits all the assumptions of the kinetic-molecular theory.
An increase in kinetic energy of water molecules produces the phase changes in a heating curve.
True As the ice melts, its temperature does not rise. All of the energy that is being put into the ice goes into the melting process and not into any increase in temperature.
At room temperature, the average kinetic energy of ice is the same as the average kinetic energy of steam.
True At a given temperature, the particles of any substance have the same average kinetic energy. At room temperature, the molecules in a sample of liquid water have the same average kinetic energy as the molecules in a sample of oxygen gas or the ions in a sample of sodium chloride.
At the boiling point of a liquid, all molecules in the liquid have enough kinetic energy to vaporize.
True Eventually, a point is reached when the molecules all throughout the liquid have enough kinetic energy to vaporize. At this point, the liquid begins to boil.
Gas pressure would result from collisions of gas molecules with the sides of a container.
True Gas pressure is the pressure that results from collisions of gas particles with an object.
Liquid in a closed system demonstrates a dynamic equilibrium between vapor and liquid.
True In the top picture, the flask of liquid ethanol has just been sealed and no vapor has accumulated, so the pressure inside is equal to the external atmospheric pressure. This is seen by the equal levels of the mercury in the U-tube. In the bottom picture, the system has been allowed to reach a dynamic equilibrium and the ethanol vapor is exerting a pressure equal to its vapor pressure.
The solid state for water is less dense than the liquid state.
True In water's diagram, the slope of the line between the solid and liquid states is negative rather than positive. The reason is that water is an unusual substance in that its solid state is less dense than the liquid state. Ice floats in liquid water. Therefore, a pressure change has the opposite effect on those two phases. If ice is relatively near its melting point, it can be changed into liquid water by the application of pressure. The water molecules are actually closer together in the liquid phase than they are in the solid phase.
Iodine can sublimate at room temperature.
True Iodine is an example of a substance for which sublimation can be readily observed at room temperature
Liquids are much more dense than gases
True Liquids are essentially not compressible and are far denser than gases.
Liquids with strong intermolecular forces show high surface tensions.
True Liquids that have strong intermolecular forces, like the hydrogen bonding in water, exhibit the greatest surface tension.
Pressure cookers increase the boiling point of water because the water vapor cannot escape.
True On the other hand, water boils at temperatures greater than 100°C if the external pressure is higher than the standard value. Pressure cookers do not allow the water vapor to escape, so the total pressure inside the cooker increases. Since water now boils at a temperature above 100°C, the food cooks more quickly.
In the orthorhombic crystal, the angles between the faces are all 90°.
True Orthorhombic: a ≠ b ≠ c; α = β = γ = 90°
The transition from solid to liquid is called melting.
True Solids melt to become liquids.
Rubber and plastic are two examples of amorphous solids.
True Some examples of amorphous solids include rubber, plastic, and gels.
At a high enough pressure, a gas can be converted to a solid
True Start right above point B on the temperature axis and follow the red line vertically. At very low pressure, the particles of the substance are far apart from one another and the substance is in the gas state. As the pressure is increased, the particles of the substance are forced closer and closer together. Eventually the particles are pushed so close together that attractive forces cause the substance to condense into the liquid state. Continually increasing the pressure on the liquid will eventually cause the substance to solidify.
A heavier rock exerts more pressure on the ground than a lighter rock.
True The force of gravity of the larger rock will be greater than a smaller rock.
The plateau portions of a heating curve indicate melting and boiling points for the material.
True The melting and boiling points of the substance can be determined by the horizontal plateaus on the curve.
The solubility of most solid substances increases as the temperature increases.
True The solubility of the majority of solid substances increases as the temperature increases.
Many solutions do not involve water.
True There are many examples of solutions that do not involve water at all, or solutions that involve solutes that are not solids.
Water undergoes three transition processes.
True Water freezes/melts, vaporizes/condenses or sublimation/deposition.
More NaCl can dissolve if more water is added to the solution.
True What if more water is added to the solution instead? Now, more NaCl would be capable of dissolving, since there is additional solvent present.
Gas molecules are far apart.
True Gases consist of very large numbers of tiny spherical particles that are far apart from one another compared to their size.
Surface tension is a measure of the elastic force on the surface of the liquid.
True The surface tension of a liquid is a measure of the elastic force in the liquid's surface.
In the cubic crystal structure
a = b= c Cubic: a = b = c; α = β = γ = 90°
One of the following statements about vapor pressure is not true
a liquid with weak intermolecular forces has a low vapor pressure A liquid with weak intermolecular forces evaporates more easily and has a high vapor pressure.
One of the following statements about absolute zero is not true
absolute zero is the temperature at which there is no electron movement Absolute zero is the temperature at which the motion of particles theoretically ceases. Absolute zero has never been attained in the laboratory, but temperatures on the order of 1 × 10−10 K have been achieved. The Kelvin temperature scale is based on this theoretical limit, so absolute zero is equal to 0 K.
Water molecules in a block of ice that is being heated
absorb energy and vibrate faster
During the process of evaporation
an increase in temperature of the liquid will increase the rate of evaporation A given liquid will evaporate more quickly when it is heated.
During the melting process, the solid and liquid states
are in equilibrium with one another
A barometer is used to measure
atmospheric pressure A barometer is an instrument used to measure atmospheric pressure.
Temperature affects all of the following parameters except
change in molecular configuration Heating up the solvent gives the molecules more kinetic energy. The more rapid motion means that the solvent molecules collide with the solute with greater frequency, and the collisions occur with more force. Both factors increase the rate at which the solute dissolves.
At 373 K, steam undergoes _____to become liquid.
condensation 373K is 100°C so steam will condense to become liquid.
Which of the following is the correct statement about the effects of temperature (T) on the average kinetic energy of gas particles (KE)?
decrease in T ---> decrease in KE The average kinetic energy of gas particles is dependent upon the temperature of the gas. As the temperature of a gas is increased, its component particles begin to move faster, resulting in an increase in their kinetic energies. As the temperature of a gas is decreased, its component particles begin to move slower, resulting in an decrease in their kinetic energies.
The solubility of gases
decreases as temperature increases
_______ is the term used for the change of state from a gas to a solid.
deposition
The vapor pressure curve shows all of the following except
diethyl ether has stronger intermolecular forces than water The boiling point of a liquid also correlates to the strength of its intermolecular forces. Recall that diethyl ether has relatively weak intermolecular forces, so the liquid has a relatively high vapor pressure at a given temperature.
All of the following are characteristics of glass except
distinct melting point characteristics: shatters in an irregular way made by cooling a mixture of materials soften when heated
All of the following except one are forms of matter
electronegativity
The boiling point is the temperature at which the vapor pressure of a liquid is equal to the _________ pressure.
external
Only one of the following effects is produced in water because of its surface tension
floating of paper clip Surface tension allows objects that are denser than water, such as the paper clip to nonetheless float on its surface.
One of the following statements about gases is incorrect
gases cannot be compressed Gases are easy to study because of the extremely large distances between the gas particles. Because there is so much space between particles, intermolecular forces can largely be ignored, which vastly simplifies any analysis of the motion exhibited by individual particles.
The earth's atmosphere exerts pressure because
gravity pulls gas molecules down Earth's atmosphere exerts pressure because gravity acts on the huge number of gas particles contained in the atmosphere, holding it in place.
_____ bonds keep the water molecules together in the solid and liquid states
hydrogen
The kinetic energy of particles in a sample of NaCl
increase with an increase in temperature In both cases, most of the particles have intermediate kinetic energies, close to the average. Notice that as temperature increases, the range of kinetic energies increases and the distribution curve "flattens out."
As pressure above the solvent _______, the amount of dissolved gas ________.
increases, increases
One of the following is not true about melting point of a solid
ionic bonds contribute to low melting points
Molecular crystals are held together by all the following forces except
ionic forces
When NaCl is added to water, all of the follow occur except
ions precipitate
Alcohol dissolved in water is an example of a _______ solution
liquid in liquid
One of the following statements about liquids is false
liquids can be compressed The primary difference between liquids and gases is that the particles of a liquid are much closer together, and there is very little empty space between them. Liquids are essentially not compressible and are far denser than gases. According to the kinetic-molecular theory for gases, any attractive forces between the particles of a gas are so minor that they can be ignored in most cases. For liquids, the intermolecular attractive forces are the only thing that keeps the particles close together.
Ice undergoes ______ at 273 K.
melting 273K = 0°C so ice will melt or freeze.
An example of a liquid in solid solution is
mercury in silver and tin
The kinetic-molecular theory assumes that
molecules are always in motion The kinetic-molecular theory is a theory that explains the states of matter and is based on the idea that matter is composed of tiny particles that are always in motion.
The forces of attraction between molecules of an ideal gas are
non-existent There are no forces of attraction or repulsion between gas particles.
One of the following statements about liquids is not true
particles at the surface are pulled upward Molecules within a liquid are pulled equally in all directions by intermolecular forces. However, molecules at the surface are pulled downward and sideways by other liquid molecules, but not upward away from the surface.
One of the following is not a characteristic of a solid
properties of a fluid
Liquid in a closed container behaves in the following way:
rate of evaporation equals rate of condensation If the water is instead kept in a closed container, the water vapor molecules do not have a chance to escape into the surroundings and so the water level does not change. As some water molecules become vapor, an equal number of water vapor molecules condense back into the liquid state. Condensation is the change of state from a gas to a liquid.
One of the following is not a cubic crystal system unit cell
rhombic cubic The cubic crystal system is composed of three different types of unit cells: (1) simple cubic, (2) face-centered cubic, and (3) body-centered cubic.
The rate at which a solute dissolves depends upon the _____ of the solute particles.
size The rate at which a solute dissolves depends upon the size of the solute particles.
Matter commonly exists in three forms or states:
solid, liquid, or gas.
Only one of the following is not used to measure air pressure
sphygmomanometer A more convenient barometer, called an aneroid barometer, measures pressure by the expansion and contraction of a small spring within an evacuated metal capsule. A manometer is used to measure the pressure of an enclosed gas sample. A traditional mercury barometer consists of an evacuated tube immersed in a container of mercury. A sphygmomanometer is used to measure blood pressure no air pressure.
The relationship between gas solubility and pressure was developed by
the English chemist William Henry
If the pressure on a gas is increased, all of the following can happen except
the gas will sublimate Things that can happen; a solid can form the gas can form a liquid the gas molecules are closer together
If the pressure on liquid water at 100° is increased,
the water remains in the liquid form
At 100°C, water undergoes _______ to become steam
vaporization
Evaporation of a liquid requires all of the following except
very high atmospheric pressure In order for a molecule to escape into the gas state, it must have enough kinetic energy to overcome the intermolecular attractive forces in the liquid. If the water is instead kept in a closed container, the water vapor molecules do not have a chance to escape into the surroundings and so the water level does not change.
The addition of NaCl to water
will reach a saturation point
