Lesson Worksheet: The Equilibrium Constant for Partial Pressures Chemistry

In this worksheet, we will practice constructing and calculating the equilibrium constant for partial pressures.

Q1:

A mixture of gases in a closed vessel at equilibrium contains three different gases: nitrogen (20 moles), hydrogen (45 moles), and ammonia (25 moles). Calculate the partial pressure of hydrogen at 40 atm.

Q2:

A sealed flask at a pressure of 1.50 atm contains dinitrogen tetroxide. The gas is found to have dissociated by 20.00% at 298 K, as shown:

NO2NO242

What is the value of the equilibrium constant, 𝐾 at 298 K? Give your answer to two decimal places.

Q3:

6.00 mol of N2 gas and 20.00 mol of H2 were allowed to react at 650 K and 50 atm of pressure. At equilibrium, 4 mol of N2 gas had been converted into ammonia according to the following reaction equation:

N()+3H()2NH()223ggg

Calculate 𝐾 for this equilibrium, giving your answer to two decimal places in scientific notation.

  • A7.81×10 atm−2
  • B8.10×10 atm−2
  • C1.80×10 atm−2
  • D2.11×10 atm−2
  • E3.78×10 atm−2

Q4:

A mixture of gases at equilibrium contains 20 moles of SO2 gas, 40 moles of O2 gas, and 40 moles of SO3 gas. What is the mole fraction of SO2 at equilibrium?

Q5:

If the value of 𝐾 at 900 K is 1.68 atm atm for the thermal decomposition of calcium carbonate, what is the partial pressure of carbon dioxide? Give your answer to two decimal places.

Q6:

A boat and its occupants floating on the surface of the sea are subject to a regular atmospheric pressure of 1 atm. A scuba diver dives off of the boat and swims downward. When the diver is 10 meters below the surface, the pressure is doubled. Use information from the pie chart to calculate the partial pressure of nitrogen 10 meters below the surface of the sea to two decimal places.

Q7:

Consider the following 𝐾 equation: 𝐾=(𝑃)(𝑃)(𝑃)NHNH322

Assuming that the pressures in a reaction between nitrogen and hydrogen to form ammonia are measured in atmospheres, what is the unit of the 𝐾 equation?

  • Aatm−2
  • Batm2
  • Catm−1
  • Datm−3
  • Eatm

Q8:

The equilibrium of a mixture of gases can be evaluated by 𝐾, the equilibrium constant for partial pressures.

Consider the following equation:

2NO()NO()224gg

What is the correct equation of 𝐾 for the equilibrium between the two different oxides of nitrogen shown?

  • A𝐾=𝑃𝑃NONO242
  • B𝐾=2𝑃𝑃NONO224
  • C𝐾=𝑃𝑃NONO242
  • D𝐾=𝑃𝑃NONO242
  • E𝐾=𝑃𝑃NONO224

Consider the following equation:

4NH()+7O()4NO()+6HO()3222gggg

What is the correct equation of 𝐾 for the equilibrium between ammonia and oxygen shown?

  • A𝐾=𝑃𝑃𝑃𝑃NOHONHO2232
  • B𝐾=𝑃𝑃𝑃𝑃NOHONHO2232
  • C𝐾=4𝑃6𝑃4𝑃7𝑃NOHONHO2232
  • D𝐾=𝑃𝑃𝑃𝑃NHONOHO3222
  • E𝐾=𝑃𝑃𝑃NHONO322

Q9:

The reaction

LiCO()LiO()+CO()2322ssg

shows the thermal decomposition of lithium carbonate in a vacuum. Which of the following is the correct equation for 𝐾?

  • A𝐾=1𝑃LiCO23
  • B𝐾=𝑃𝑃COLiCO223
  • C𝐾=𝑃𝑃𝑃COLiOLiCO2223
  • D𝐾=𝑃𝑃𝑃LiCOLiOCO2322
  • E𝐾=𝑃CO2

Q10:

Choose the correct expression for the 𝐾 of the following reaction:

2NOBr()2NO()+Br()ggg2

  • A𝐾=(𝑃)(𝑃)(𝑃)NOBrNOBr2
  • B𝐾=(𝑃)(𝑃)(𝑃)NOBrNOBr2
  • C𝐾=(𝑃)(𝑃)NOBr2
  • D𝐾=(𝑃)(𝑃)(𝑃)NOBrNOBr2
  • E𝐾=(𝑃)(𝑃)(𝑃)NOBrNOBr2

This lesson includes 16 additional questions and 28 additional question variations for subscribers.

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