Question 1

A rigid, sealed 2.0 L container holds 1.0 mole of an ideal gas at a temperature of

300 K

. If the absolute temperature of the gas is doubled to

600 K

while the volume remains constant, which statement best predicts the effect on the pressure of the system and provides the correct justification according to the Kinetic Molecular Theory?

Accepted Answer

The pressure will double because the average kinetic energy of the molecules increases, leading to more frequent and more forceful collisions with the container walls.

Answer

The pressure will remain constant because the volume of the container and the number of moles of gas have not changed.

Answer

The pressure will double because the molecules expand in size as they regain thermal energy, increasing the total volume occupied by the particles.

Answer

The pressure will decrease by half because the increase in temperature causes gas molecules to move slower and strike the walls with less momentum.

Question 2

An exothermic reaction reaches equilibrium in a sealed flask according to the equation:

300 K

. If the temperature of the system is increased at constant volume, what will be the effect on the equilibrium constant (

600 K

) and the concentration of product

C

?

Accepted Answer

K_{eq}

will decrease and the concentration of

C

will decrease.

Answer

K_{eq}

will stay the same, but the concentration of

C

will decrease due to the shift in equilibrium.

Answer

K_{eq}

will decrease, but the concentration of

C

will increase to counteract the heat.

Answer

K_{eq}

will increase and the concentration of

C

will increase.

Question 3

A simple circuit consists of a battery with a constant voltage

300 K

and a single resistor with resistance

600 K

. If the resistance of the resistor is quadrupled while the voltage remains constant, what is the predicted effect on the power dissipated by the circuit?

Accepted Answer

The power dissipated will decrease to one-fourth of its original value.

Answer

The power dissipated will remain the same because voltage is constant.

Answer

The power dissipated will quadruple.

Answer

The power dissipated will decrease to one-sixteenth of its original value.

Question 4

In a hypothetical aqueous reaction

300 K

, the rate law is determined to be

600 K

. If the volume of the reaction container is suddenly halved at a constant temperature, which of the following best predicts the effect on the initial rate of the reaction?

Accepted Answer

The initial rate will increase by a factor of 8.

Answer

The initial rate will increase by a factor of 4.

Answer

The initial rate will increase by a factor of 2.

Answer

The initial rate will decrease by a factor of 8.

Question 5

A satellite is in a stable circular orbit around a planet at a distance

300 K

from the planet's center. If the orbital radius of the satellite is increased to

600 K

, what is the predicted effect on the satellite's orbital speed

C

?

Accepted Answer

The orbital speed will decrease to one-half of its original value.

Answer

The orbital speed will decrease to one-fourth of its original value.

Answer

The orbital speed will remain constant because the mass of the planet has not changed.

Answer

The orbital speed will decrease to one-sixteenth of its original value.

Question 6

A buffer solution is prepared with equal concentrations of a weak acid

300 K

and its conjugate base

600 K

. If the total volume of the buffer is doubled by adding pure distilled water, what is the predicted effect on the

C

of the solution and the buffer capacity?

Accepted Answer

The

300 K

will remain essentially unchanged, but the buffer capacity will decrease.

Answer

The

300 K

will remain essentially unchanged and the buffer capacity will remain constant.

Answer

The

300 K

will decrease significantly and the buffer capacity will decrease.

Answer

The

300 K

will increase significantly and the buffer capacity will increase.

Question 7

A simple pendulum of length

300 K

has a period

600 K

on Earth. If the pendulum is moved to a moon where the gravitational acceleration is

C

that of Earth's gravity

g

, what is the predicted effect on the period of the pendulum?

Accepted Answer

The period will increase to

300 K

.

Answer

The period will decrease to

300 K

.

Answer

The period will remain

300 K

because it only depends on the length of the string.

Answer

The period will increase to

300 K

.

Question 8

A parallel-plate capacitor with a vacuum between its plates is connected to a battery of constant voltage

300 K

. If the distance

600 K

between the plates is doubled while the capacitor remains connected to the battery, what is the predicted effect on the electric field

C

between the plates and the charge

g

stored on the capacitor?

Accepted Answer

Both the electric field

300 K

and the stored charge

600 K

will decrease to half of their original values.

Answer

The electric field

300 K

will decrease to half, but the stored charge

600 K

will remain constant.

Answer

The electric field

300 K

will double, and the stored charge

600 K

will double.

Answer

The electric field

300 K

will decrease to one-fourth, and the stored charge

600 K

will decrease to one-fourth.

Question 9

An ideal gas is contained in a cylinder with a movable piston at a constant temperature. If the external pressure on the piston is tripled and the system is allowed to reach a new equilibrium, which of the following best predicts the change in the frequency of collisions between the gas molecules and the container walls?

Accepted Answer

The frequency of collisions will increase because the density of the gas molecules increases as the volume decreases to one-third of its original value.

Answer

The frequency of collisions will decrease because the higher pressure compresses the molecules, reducing their average speed.

Answer

The frequency of collisions will remain the same because the temperature, and thus the average kinetic energy of the molecules, is constant.

Answer

The frequency of collisions will triple because the force of each individual collision triples to match the external pressure.

Question 10

A chemical reaction

300 K

is found to have the overall rate law

600 K

. If the volume of the reaction vessel is tripled at a constant temperature, what is the predicted effect on the initial rate of the reaction?

Accepted Answer

The initial rate will decrease to one-ninth of its original value.

Answer

The initial rate will remain the same because the temperature is constant.

Answer

The initial rate will increase by a factor of nine.

Answer

The initial rate will decrease to one-third of its original value.