# Worksheet: Equilibrium Constants and Pressures

In this worksheet, we will practice converting between partial pressures and equilibrium constants for reactions involving at least one gas.

Q1:

What is the pressure of in an equilibrium gas mixture containing 0.45 atm of , 1.95 atm of , and 0.95 atm of at ?

Q2:

What is the pressure of in an equilibrium mixture of , , and if the pressure of in this mixture is 0.115 atm and the pressure of is 0.450 atm?

• A atm
• B 20 atm
• C atm
• D atm
• E atm

Q3:

One of the important reactions in the formation of smog is represented by the equation: In a gas mixture, the initial partial pressures of and are both equal to atm. The partial pressures of all gases are 1.0 atm under standard conditions. Calculate the partial pressure of in the gas mixture at equilibrium.

• A atm
• B atm
• C atm
• D atm
• E atm

Q4:

What is the partial pressure of in an equilibrium mixture that results from the decomposition of with an initial pressure of 0.824 atm? Assume that all pressures in are expressed relative to a standard pressure of 1.00 atm and that changes in the pressure of are small enough to be neglected.

Q5:

At and 1 atm, the partial pressures in an equilibrium mixture of and are = 0.70 atm and = 0.30 atm.

Nitrogen dioxide dimerizes to form dinitrogen tetroxide . How will the pressures of and change if the total pressure increases to 9.0 atm?

• AThe partial pressure of will increase, while that of will decrease.
• BBoth will decrease.
• CThe partial pressure of will decrease, while that of will increase.
• DBoth will increase.
• EThey will both stay the same.

Calculate to 1 significant figure the equilibrium partial pressure of at 9.0 atm and .

Q6:

Consider the reaction between and at K. Under standard conditions, each species has a partial pressure of 1 atm. If a flask contains 0.500 atm of and 0.500 atm of , calculate the partial pressure of hydrogen at equilibrium.

• A 0.500 atm
• B atm
• C atm
• D atm
• E atm

Q7:

Liquid is dark blue at low temperatures, but the color fades and becomes greenish at higher temperatures as the compound decomposes to and . At 25℃, a value of = 1.91 has been established for this decomposition. If 0.236 moles of are placed in a 1.52-L vessel at 25℃, what is the equilibrium partial pressure of ?

Q8:

Nitrogen oxides are air pollutants produced by the reaction of nitrogen and oxygen at high temperatures. At , the value of the equilibrium constant for the reaction, , is . Calculate the equilibrium concentration of in air at if = 0.036 M and = 0.0089 M when equilibrium is reached.

• A 0.88 M
• B M
• C 0.78 M
• D M
• E M

Q9:

Sodium sulfate decahydrate, , dehydrates according to the equation shown. In the equilibrium constant , partial pressures are defined relative to a standard pressure of 1 atm. Calculate the partial pressure of water vapor at equilibrium with a mixture of and at .

• A 24.4 atm
• B atm
• C atm
• D atm
• ENot enough information has been provided.

Q10:

A sample of ammonium chloride was heated in a closed container. Ammonium chloride thermally decomposes according to the equation shown. At equilibrium, the pressure of was found to be 1.75 atm. Using a standard gas pressure of 1.00 atm, calculate the value of the equilibrium constant for the decomposition at this temperature.

Q11:

Consider the shown reaction.

The equilibrium constant for this reaction has a value of at a temperature of K. What would be the partial pressure of in an equilibrium mixture that is at K and contains at a partial pressure of 0.1 bar and at a partial pressure of 0.1 bar?

• A bar
• B bar
• C bar
• D bar
• E bar

Q12:

Nitric oxide and chlorine react reversibly to form nitrosyl chloride according to the following equation: In a gas mixture at equilibrium, the partial pressures of , and are 0.050 atm, 0.30 atm and 1.2 atm, respectively. Using a standard gas pressure of 1.0 atm, calculate the equilibrium constant for this reaction.

• A80
• B96
• C
• D
• E