The equilibrium constant, K

Answer Key - Grade 10 Science Worksheet - Challenge Me

Circle the best answer, or write your answer on the line.

1. 1.

   At equilibrium for H₂ + I₂ ⇌ 2 HI, [H₂] = 0.1, [I₂] = 0.1 and [HI] = 0.7 mol/L. What is K, Ari?

   49
2. 2.

   At equilibrium for H₂ + I₂ ⇌ 2 HI, [H₂] = 0.04, [I₂] = 0.04 and [HI] = 0.2 mol/L. What is K, Esme?

   25
3. 3.

   H₂ + I₂ ⇌ 2 HI has K = 50 at 400 °C. What is K for 2 HI ⇌ H₂ + I₂ at 400 °C, Jun?

   • 50
   • −50
   • 0.02
4. 4.

   For N₂O₄ ⇌ 2 NO₂, K = 0.2 and a mixture has Q = 0.5. Which way does it go, Kira?

   • Toward N₂O₄
   • Toward NO₂
   • It stays put
5. 5.

   Reaction X has K = 1 × 10⁸. What does K tell us about it, Luz?

   • It goes nearly to products
   • It needs a catalyst to get going
   • It is very fast
6. 6.

   Milo says adding more N₂O₄ raises K for N₂O₄ ⇌ 2 NO₂. Agree or disagree?

   • Disagree: K stays; the mix shifts
   • Agree: K counts the N₂O₄ added
   • Agree: more reactant means a new, bigger K
7. 7.

   Noah says a reaction with a large K must be fast. Agree or disagree?

   • Agree: large K means fast
   • Agree: fast reactions have big K
   • Disagree: K shows extent, not speed
8. 8.

   Pia says removing some product lowers K. Agree or disagree?

   • Agree: K follows the product
   • Agree: less product means a smaller K
   • Disagree: K is fixed at that temperature
9. 9.

   H₂ + I₂ ⇌ 2 HI has K = 25 at some temperature, with [H₂] = [I₂] = 0.10 mol/L. What is [HI], Tala?

   • 0.25 mol/L
   • 2.5 mol/L
   • 0.50 mol/L
10. 10.

    Which change gives a new value of K, Zee?

    • Adding a catalyst
    • Changing the temperature
    • Adding more of the reactant gas