Question 1

Henry's law is  .Which statement BEST describes the meaning of this law?
A) As the pressure above a gas in solution decreases, the concentration of gas in solution increases.
B) As the pressure above a gas in solution increases, the concentration of gas in solution also increases.
C) As the pressure above a gas in solution increases, the concentration of gas in solution decreases.
D) As the concentration of a gas in solution increases, Henry's constant increases.
E) As the concentration of a gas in solution decreases, Henry's constant decreases.

Accepted Answer

B

Question 2

Air is primarily composed of nitrogen (594 torr)and oxygen (160 torr).There is also carbon dioxide and water vapor in the air.Assuming that atmospheric pressure is 760 torr, what is the partial pressure of carbon dioxide and water vapor combined?
A) 1514 torr
B) 754 torr
C) 500 torr
D) 166 torr
E) 6 torr

Accepted Answer

The total atmospheric pressure is the sum of the partial pressures of all gases present. Given nitrogen at 594 torr and oxygen at 160 torr, their combined pressure is 754 torr. Subtracting this from the total atmospheric pressure of 760 torr gives 6 torr for the combined partial pressure of carbon dioxide and water vapor.

Question 3

Which statement BEST describes how the kinetic molecular view of gases can be used to explain the effect of gas temperature on gas pressure?
A) Gas pressure and gas temperature are unrelated.
B) The effect of temperature on pressure depends upon the gas.
C) As temperature increases, the particles are damaged, slowing them down and decreasing the number of collisions against the beaker; therefore the pressure decreases.
D) As temperature increases, the particles are split apart so that there are more collisions against the beaker and the pressure increases.
E) As temperature increases, the speed of particles increases, so there are more collisions against the beaker and the pressure increases.

Accepted Answer

The kinetic molecular theory explains that as temperature increases, the kinetic energy of gas particles increases, leading to an increase in their speed. This results in more frequent and forceful collisions with the walls of their container, thereby increasing the gas pressure.

Question 4

Three boxes, each containing molecules in the gas phase, are illustrated below.Which box would you expect to have the highest pressure? 
A) box A
B) box B
C) box C
D) boxes A and B have the same highest pressure.
E) boxes A and C have the same highest pressure.

Accepted Answer

The answer of Three boxes, each containing molecules in the...

Question 5

This diagram shows balloons of various sizes filled with helium gas.Balloon A is at STP.If you heat balloon A, which balloon would you predict would BEST represent the new size of balloon A? 
A) balloon B
B) balloon C
C) balloon D
D) either balloon B or D
E) either balloon C or D

Accepted Answer

The answer of This diagram shows balloons of various sizes...

Question 6

Which of the following statements about pressure is FALSE?
A) Common units of pressure include atmospheres, psi, and Pa.
B) Pressure is the result of the force of atoms or molecules colliding with the walls of their container.
C) Pressure is defined as force applied to a given area.
D) Pressure increases as the number of collisions of the gas particles with their container decreases.
E) Atmospheric pressure is less than 1 atm at elevations higher than sea level.

Accepted Answer

Pressure increases with an increase in the number of collisions of gas particles with their container, not a decrease.

Question 7

Which statement about the density of gases is FALSE?
A) 
B) Gases with greater molar masses have greater densities.
C) At STP, the molar volume for gases varies widely.
D) Oxygen is denser than hydrogen.
E) A helium balloon floats in air because helium is less dense than air.

Accepted Answer

The answer of Which statement about the density of gases...

Question 8

Balloon A is placed into a container that has a higher pressure than atmospheric pressure.Which of the following statements about the relationship between pressure and volume is TRUE?
A) The pressure of the gas on the outside of the balloon forces gas inside, making balloon A bigger.
B) The pressure on the outside of the balloon will shrink the gas particles, decreasing the volume of the balloon.
C) The pressure on the outside of the balloon will slow down the gas particles, making the balloon smaller.
D) The pressure outside the balloon will compress the air in the balloon, making the balloon smaller.
E) External pressure does not affect the volume of the balloon.

Accepted Answer

The pressure outside the balloon will compress the air in the balloon, making the balloon smaller, according to Boyle's Law, which states that the pressure of a gas increases as the volume decreases, provided the temperature is constant.

Question 9

Which atom has the highest electronegativity in this molecule of acetone? 
A) carbon
B) oxygen
C) hydrogen
D) carbon and hydrogen
E) They all have the same electronegativity.

Accepted Answer

The answer of Which atom has the highest electronegativity in...

Question 10

You boil a pot of water (H₂O)to make spaghetti and, when the water reaches its boiling point, you notice that it bubbles.What are these bubbles composed of? A) nothing B) H₂ C) O₂ D) H₂ and O₂ E) H₂O

Accepted Answer

The bubbles are composed of water vapor, which is H2O in its gaseous form. The chemical formula H₂O represents H2O, indicating water.

Question 11

One of the symptoms of the bends is joint pain.Why does joint pain occur with the bends?
A) Nitrogen bubbles expand in the joints as pressure decreases.
B) The bends causes muscle spasms, which leads to joint pain.
C) The bends causes a loss of cartilage in joints.
D) Lactic acid is released as a stress response.
E) The reason for joint pain is unknown.

Accepted Answer

Nitrogen bubbles form and expand in the joints (and other parts of the body) as a diver ascends and the pressure decreases, leading to the joint pain associated with the bends (decompression sickness).

Question 12

Which of the following statements BEST describes the process that occurs when air is inhaled into the lungs?
A) The diaphragm moves up, the lungs expand, pressure decreases, and air is inhaled.
B) The diaphragm moves down, the lungs expand, pressure decreases, and air is inhaled.
C) The diaphragm moves up, the lungs contract, pressure increases, and air is inhaled.
D) The diaphragm moves down, the lungs expand, pressure increases, and air is inhaled.
E) The diaphragm moves down, the lungs contract, pressure decreases, and air is inhaled.

Accepted Answer

When you inhale, the diaphragm contracts and moves downward. This increases the space in the chest cavity, the lungs expand, and the pressure inside the lungs decreases. Air then flows in to equalize the pressure.

Question 13

You have a balloon containing 1.4 L of gas in it at standard temperature and pressure.Which conversion factor would you use to convert this number to moles? A) 1 mol/22.4 L B) 1 L/22.4 mol C) 22.4 L/1 mol D) 6.02 × 10²³ L/1 mol E) 1 L/6.02 × 10²³ mol

Accepted Answer

At standard temperature and pressure (STP), 1 mole of an ideal gas occupies 22.4 liters. Therefore, to convert liters to moles, you would use the conversion factor 1 mol/22.4 L.

Question 14

Which bond in acetone, shown below, is correctly labeled with a dipole arrow? 
A) structure a
B) structure b
C) structure c
D) structure d
E) structure e

Accepted Answer

The answer of Which bond in acetone, shown below, is...

Question 15

Which of the following changes is NOT correctly labeled as a chemical reaction or a change of state?
A) rust forming on metal, a chemical reaction
B) steam coming off of a cup of coffee, a change of state
C) an ice cube melting in a drink, a change of state
D) the combustion of gasoline to give carbon dioxide and water, a chemical reaction
E) bubbles forming in a just-opened can of soda, a chemical reaction

Accepted Answer

Bubbles forming in a just-opened can of soda are due to the release of carbon dioxide gas that was dissolved under pressure, not a chemical reaction. This is a physical change related to the change in pressure, allowing the gas to escape from the liquid.

Question 16

How does the pressure of a gas change when it is heated in a sealed container with a constant volume? (Note: It is not a good idea to actually do this without special equipment) A) It will not change because there is no relationship between temperature and pressure. B) It will increase because P_iT_i = P_fT_f. C) It will decrease because P_iT_i = P_fT_f. D) It will increase because P_i/T_i = P_f/T_f. E) It will decrease because P_i/T_i = P_f/T_f.

Accepted Answer

The pressure of a gas increases when heated in a sealed container due to the direct relationship between temperature and pressure, as described by Gay-Lussac's law. This law states that the pressure of a gas of fixed mass and fixed volume is directly proportional to the gas's absolute temperature.

Question 17

What is the molecular geometry of the carbon indicated by the arrow in this molecule of acetone? 
A) linear
B) bent
C) trigonal planar
D) trigonal pyramidal
E) tetrahedral

Accepted Answer

The answer of What is the molecular geometry of the...

Question 18

Imagine that you have a beaker of gas molecules as shown in the image below.If all of the gas in the beaker is transferred to a new beaker half the size of the original beaker, while maintaining the same temperature, which view BEST represents what the gas would look like? 
A) diagram a
B) diagram b
C) diagram c
D) diagram d
E) diagram e

Accepted Answer

The answer of Imagine that you have a beaker of...

Question 19

At 1.0 atm, the air in a pilot's lungs occupies 0.50 L.The pilot ascends to an altitude where the pressure is 0.35 atm.If the pilot holds her breath during her ascent, what is the new volume of the air in the pilot's lungs?
A) 0.18 L
B) 0.70 L
C) 0.85 L
D) 1.4 L
E) 5.7 L

Accepted Answer

Using Boyle's Law (P1V1 = P2V2), where P1 = 1.0 atm, V1 = 0.50 L, and P2 = 0.35 atm, we can solve for V2: V2 = (P1V1)/P2 = (1.0 atm * 0.50 L) / 0.35 atm = 1.4 L.

Question 20

In which of the following statements is the gas variable (in italics)correctly described?
A) Temperature is a measure of the space occupied by a gas.
B) Volume increases as the collisions of gas particles with the walls of the container increases.
C) Temperature is related to the average speed of gas particles.
D) The number of moles of a gas decreases as the volume of the gas increases.
E) When gas particles move faster, the pressure of the gas must increase.

Accepted Answer

Temperature is related to the average kinetic energy, and thus the average speed, of gas particles.

Quiz 7: Changes of State and Gas Laws

Henry's law is .Which statement BEST describes the meaning of this law?

Air is primarily composed of nitrogen (594 torr) and oxygen (160 torr) .There is also carbon dioxide and water vapor in the air.Assuming that atmospheric pressure is 760 torr, what is the partial pressure of carbon dioxide and water vapor combined?

Which statement BEST describes how the kinetic molecular view of gases can be used to explain the effect of gas temperature on gas pressure?

Three boxes, each containing molecules in the gas phase, are illustrated below.Which box would you expect to have the highest pressure?

This diagram shows balloons of various sizes filled with helium gas.Balloon A is at STP.If you heat balloon A, which balloon would you predict would BEST represent the new size of balloon A?

Which of the following statements about pressure is FALSE?

Which statement about the density of gases is FALSE?

Balloon A is placed into a container that has a higher pressure than atmospheric pressure.Which of the following statements about the relationship between pressure and volume is TRUE?

Which atom has the highest electronegativity in this molecule of acetone?

You boil a pot of water (H₂O) to make spaghetti and, when the water reaches its boiling point, you notice that it bubbles.What are these bubbles composed of?

One of the symptoms of the bends is joint pain.Why does joint pain occur with the bends?

Which of the following statements BEST describes the process that occurs when air is inhaled into the lungs?

You have a balloon containing 1.4 L of gas in it at standard temperature and pressure.Which conversion factor would you use to convert this number to moles?

Which bond in acetone, shown below, is correctly labeled with a dipole arrow?

Which of the following changes is NOT correctly labeled as a chemical reaction or a change of state?

How does the pressure of a gas change when it is heated in a sealed container with a constant volume? (Note: It is not a good idea to actually do this without special equipment)

What is the molecular geometry of the carbon indicated by the arrow in this molecule of acetone?

Imagine that you have a beaker of gas molecules as shown in the image below.If all of the gas in the beaker is transferred to a new beaker half the size of the original beaker, while maintaining the same temperature, which view BEST represents what the gas would look like?

At 1.0 atm, the air in a pilot's lungs occupies 0.50 L.The pilot ascends to an altitude where the pressure is 0.35 atm.If the pilot holds her breath during her ascent, what is the new volume of the air in the pilot's lungs?

In which of the following statements is the gas variable (in italics) correctly described?