States of Matter #1
A student uses 0.0821 L• atm/mol • K as the value of the gas constant. What is most likely true about the variables in the ideal gas law?
V has the units of liters, and T has the units of kelvin.
Which proportionality applies to Avogadro's law?
V ∝ n
Which equation agrees with the ideal gas law?
V1/T1 = V2/T2
A balloon that had a volume of 3.50 L at 25.0°C is placed in a hot room at 40.0°C. If the pressure remains constant at 1.00 atm, what is the new volume of the balloon in the hot room?
2.19 L 3.33 L 3.68 L
What is the temperature of 0.750 mol of a gas stored in a 6,850 mL cylinder at 2.21 atm?🔹The Ideal Gas Law
246 K
What is the pressure of 0.540 mol of an ideal gas at 35.5 L and 223 K?
28.2 kPa
Which container has gas stored at the highest temperature?
3
Avogadro's law and Charles's law describe a proportionality of the volume of a gas when the pressure is constant. Which describes the proportionality that allows these laws to be combined when describing a gas?
Volume is directly proportional to moles (Avogadro's law) and to temperature (Charles's law).
Which statement would be the most useful for deriving the ideal gas law?
Volume is directly proportional to the number of moles.
Which equation is derived from the combined gas law?
V₁/T₁ = V₂/T₂
Water can dissolve other substances. Which factor best contributes to this property of water?
Water particles are not fixed in place.
The particles in water have less mobility than the particles in oxygen. Which statement best explains this observation?🔹
Water particles have strong intermolecular forces.
Which is the best example of immiscible liquids?
a polar liquid and a nonpolar liquid that do not dissolve into one another
This situation best models the formation of which type of solid?
an amorphous solid because the particles do not have a regular structure
Valerie wants to examine the properties of a thick liquid but is finding it difficult to pour the liquid into a beaker. She needs to finish her investigation before the end of class. Which method will allow her to pour the liquid easily?
applying heat to the liquid
Which two conditions can limit the usefulness of the kinetic-molecular theory in describing gas behavior?
high pressure and low temperatures
hich row of the table and which observation would the student fill?
row 1, volume decreases when pressure increases
Which molecules would most likely cause a liquid to have the lowest viscosity?
small, nonpolar molecules
A substance is tested in a lab. It is found to maintain a unique shape and is a good conductor of electricity. If it is made up of electrons, protons, and neutrons, what state of matter is this substance most likely to be?▪️
solid
According to the kinetic-molecular theory, the average kinetic energy of gas particles depends on which factor?
temperature
Which constants would most likely be filled in the first row of the table?
temperature and moles of gas
What are the variables for this piston?
temperature only temperature and volume volume and number of molecules
If the pressure, volume, and temperature of a gas are known, which can most likely be found by using the ideal gas law?
the molar amount of the gas
Which is an example of a plasma that occurs in nature?
the radiant sun
Which arrow would most likely represent the phase change that involves the same amount of energy as arrow 1?
4
Five gases combined in a gas cylinder have the following partial pressures: 3.00 atm (N2), 1.80 atm (O2), 0.29 atm (Ar), 0.18 atm (He), and 0.10 atm (H). What is the total pressure that is exerted by the gases?
5.37 atm
Which best explains the relationship between evaporation and temperature?
A liquid evaporates faster at higher temperatures because more particles have a higher speed and can overcome attractions in the liquid.
A solid substance turns into a liquid. Which best describes this change?
A substance that has a specific shape and volume changes to a substance that has a specific volume.
Which law is based on the graph that is shown below? | * | . . * |___ ___*___*
Boyle's law
Which law relates temperature, pressure, volume, and the number of moles of a gas under perfect conditions?
Boyle's law Charles's law ideal gas law
Which arrow represents the transition in which dew is formed?
2
Which energy change occurs during boiling?
Heat energy is absorbed by the substance.
Which best describes the energy change that takes place during deposition?
Heat energy is released by the substance.
Substance X has a fixed volume, and the attraction between its particles is strong. Substance Y has widely spread out particles and can be compressed. What can most likely be concluded about these substances?
Substance X is a solid, and substance Y is a plasma.
Which description best characterizes the motion of particles in a solid?
vibrating around fixed positions
A graph of gas pressure versus the number of particles in a container is a straight line. Which other relationship will have a similar graph?
volume versus temperature, because they are also directly proportional
Jean has a sample of a liquid. If she changes the liquid's phase by [____________________] it, the molecules will spread out, allowing the sample to expand and fill a container of any shape or volume.
-evaporating
In which region is the substance in both the solid phase and the liquid phase?
1 2 4
Which arrows represent the phase transitions in which heat energy is gained?
1, 2, and 3 2, 3, and 5 3, 4, and 5
Which law states that the volume and absolute temperature of a fixed quantity of gas are directly proportional under constant pressure conditions?
Charle's law
Which laws can be combined to form the ideal gas law?
Charles's law, Avogadro's law, and Boyle's law
Which law is described by saying that doubling the absolute temperature will double the pressure of a sample of gas in a rigid container?
Gay-Lussac's law
Consider a balloon that has a volume V. It contains n moles of gas, it has an internal pressure of P, and its temperature is T. If the balloon is heated to a temperature of 15.5T while it is placed under a high pressure of 15.5P, how does the volume of the balloon change?
It stays the same.
A light twig is barely floating on the surface of water. What will most likely happen to the twig if a drop of dishwashing detergent is added near it?
It will sink because soap disrupts the intermolecular forces of water.
If a gas is moved from a large container to a small container but its temperature and number of moles remain the same, what would happen to the pressure of the gas?
It would increase.
What happens when the kinetic energy of molecules increases so much that electrons are released by the atoms, creating a swirling gas of positive ions and negative electrons?
Matter changes to a plasma state.
Which statement best describes the process that arrow 1 represents?
Molecules are speeding up as boiling occurs.
Temperature depends on the average kinetic energy of the particles in a sample. How does this help with explaining why a plasma-based light does not have a high temperature?
Most particles in the plasma are heavy and slow.
How does the motion of particles in the sun's plasma compare to the motion of particles in a solid?🔹
Particles in the plasma move randomly, but particles in a solid vibrate in one place.
Which equation represents the combined gas law?
P₁V₁/T₁ = P₂V₂/T₂
What happens when a solid is dissolved into a liquid?
Solid particles become evenly dispersed among liquid particles.
Which is an example of the kinetic-molecular theory not holding true for a gas?
The attraction between particles causes a gas to condense at low temperatures.
Which describes the volume of 1 mol of gas at standard temperature and pressure?
The volume is the same for any gas.
Which best explains why a crystal is incompressible?
There is little, if any, space left between its adjacent molecules.
Which statement about gases is true?
They are made up of hard spheres that are in random motion.
Glycerol boils at a higher temperature than water. What does this indicate about the attractive forces of glycerol?
They are stronger than those in water.
Which postulate of the kinetic-molecular theory applies to the particles of a liquid?
They have enough kinetic energy to easily slide by each other.
Which labels belong in the cells marked X and Y?
X: High Y: High
At what temperature is the boiling point of this substance?🔹
at 120°C
Which is an example of plasmas in nature?
auroras
Which change of state involves a release of energy?
condensation
Which step will decrease the pressure of a gas inside a closed cubical container?
decreasing the temperature inside the container
Which event is most likely occurring?
effusion because there is a movement of a gas through a small opening into a larger volume
Which example involves a phase change in which heat energy is released by the substance?
freezing ice cream
Water is initially present in a state where its molecules are far apart. During a change of state, its molecules slow down. Which change of state has most likely taken place?
from a gas to a liquid
Melting can be best described as a process in which molecules
gain enough kinetic energy to get past each other.
Water's molar mass is 18.01 g/mol. The molar mass of glycerol is 92.09 g/mol. At 25°C, glycerol is more viscous than water. Which substance has the stronger intermolecular attraction?
glycerol because it is more viscous and has a larger molar mass
If gas particles start colliding with the walls of their metallic container with increased force, what is their direct effect?
higher gas pressure
The particles of a gas inside a balloon are experiencing an increase in their average kinetic energy and the number of collisions with the wall of the balloon. What is the most likely outcome?
higher gas pressure inside the balloon
Which sequence represents the relationship between temperature and volume as explained by the kinetic-molecular theory?
higher temperature → more kinetic energy → more space between particles → higher volume
According to the kinetic-molecular theory, the collision between two ideal gas particles is a result of
neither attraction nor repulsion.
A plasma that has particles that never collide frequently enough to exchange kinetic energy and never reach a temperature equal to the surroundings is categorized as a
nonthermal plasma.
A scientist is measuring the pressure that is exerted by each of the following gases in the atmosphere: carbon dioxide, oxygen, and nitrogen. Which term most likely describes what she is measuring?
partial pressure
Which state of matter is characterized by ionized particles, no definite shape or volume, and good electrical conductivity?
plasma
What are thermal plasmas?
plasmas that reach a temperature equal to their surroundings
What are the variables in Gay-Lussac's law?
pressure and temperature
Which low-energy state of condensed matter is characterized by structural rigidity and resistance to changes of shape or volume?
solid
Which term best describes the substances that cause oil and water molecules in salad dressing to interact and mix?
surfactants
Which reason best explains why plasmas are good conductors of electricity?
They have mobile charged particles. They are made up of particles in fixed positions. They have slow-moving nuclei that carry electricity.
Which device involves the use of plasma in technology?
arc welder
Which are assumed to be constant while using the combined gas law? (gase laws)
number of moles
A substance is made up of slow-moving particles that have very little space between them. Based on this information, what can most likely be concluded about this substance?
It is not a gas because its particles do not have large spaces between them.
Which is an aspect of the kinetic-molecular theory and can be used to explain the behavior of plasmas?
Particles exchange energy through elastic collisions.
Which statement best explains what happened?
The soap reduced the surface tension behind the boat, causing both water molecules and the boat to be pulled forward.
On a temperature versus time graph, how does the temperature at the beginning of a change of state compare with the teperature at the end of the change?
always the same
Liquids and solids are referred to as "condensed phases" because the attractive forces
cause molecules to become stationary. leave little space between the molecules. create large spaces between the molecules.
Which diagram represents the phase that occurs after a solid melts?
diagram 1
Which term best describes liquid behavior under pressure?
incompressible
Which best defines partial pressure in a mixture of gases?
sum of the individual pressures that are exerted by two or more gases
What is produced on the top of a pool of water by the mutual attraction between water molecules?
surface tension
If the pressure, volume, and the number of moles of a gas are known, which is needed to calculate the universal gas constant from the ideal gas law?
the temperature of the gas
A graph of gas pressure versus the number of particles in a container is a straight line. Which other relationship will have a similar graph🔹
volume versus temperature, because they are also directly proportional
At what temperature does the solid start melting?
0°C
Based on the information in the graph, which statement best applies to a gas?
Its particles have the highest average kinetic energy.
The volume of a gas is 450 mL when its pressure is 1.00 atm. If the temperature of the gas does not change, what is the pressure when its volume is changed to 2.00 L?
0.225 atm
A gas cylinder contains 2.0 mol of gas X and 6.0 mol of gas Y at a total pressure of 2.1 atm. What is the partial pressure of gas Y?🔹Gas Laws
1.6 atm
Which arrow would most likely represent the phase change that occurs when silver is poured into a mold and cools to become a solid bar?
5
If two gases are present in a container, the total pressure in the container is equal to
the sum of the pressures that are exerted by each of the two gases. the sum of the pressures that each gas would exert if they occupied half the volume.
The closeness of particles of gas and their low speeds allow intermolecular forces to become important at certain pressures and temperatures. Which best describes this statement?
This is a limitation of the kinetic-molecular theory.
Why are liquids well suited for hydraulics?
Liquids are incompressible.
A perfume bottle is dropped in the corner of a room. The odor of the perfume can be detected on the other side of the room. Which statement best describes this observation?
Particles are moving from regions of high concentration to low concentration.
Which statement best describes the collisions of gas particles according to the kinetic-molecular theory?
As particles travel in straight lines, their paths sometimes meet, and then they bounce apart with no gain or loss of energy.
Which law states that the volume of a gas is proportional to the moles of the gas when pressure and temperature are kept constant?
Avogadro's law
Which observation indicates that the kinetic-molecular theory has limited use for describing a certain gas?
Increasing pressure is causing a smaller change in gas volume.
Which statement best describes the compressibility of a gas?
Increasing the pressure on a gas decreases the volume.
A gas has experienced a small increase in volume but has maintained the same pressure and number of moles. According to the ideal gas law, how has the temperature of the gas changed?
It has increased slightly.
The absolute temperature of a gas is increased four times while maintaining a constant volume. What happens to the pressure of the gas?
It increases by a factor of four.
Bromine gas in a container is heated over a flame. What happens to the average kinetic energy of the bromine particles?
It increases quickly.
"When nitrogen is liquefied, heat is released." Is this statement true or false?
It is true because heat is released when a gas changes to a liquid.
Which statement best explains why heating a liquid affects its viscosity? (liquids)
The molecules move faster at higher temperatures and overcome attractions more easily.
Which best compares the particles of the substance when it is in region 1 with the particles of the substance when it is in region 3?
The particles are more orderly in region 1.
Which statement can best be concluded from the ideal gas law?
The product of pressure and volume of an ideal gas is proportional to the absolute temperature.
PV ∝ nT What does this best represent?
ideal gas law
Which of the following best identifies where long-range order would be found? (gases)
in crystalline solids
