Unit 7 Equilibrium (7.1-7.8)

For the reaction...

SO_2(g) + O_2(g) ⇌ SO_3(g)

If the concentration of SO_2(g) is increased, the equilibrium of the reaction will ___________.

• shift to the left

• shift to the right

• not shift

For the reaction...

SO_2(g) + O_2(g) ⇌ SO_3(g)

If the equilibrium shifts to the right, the concentration of O_2(g) will ___________.

• increase

• decrease

• remain the same

The equilibrium constant, Kc, for the following reaction is 6.44 x 10⁵ at 230°C. 2NO_(g) + O_2(g) ⇌ 2NO_2(g).

Calculate the equilibrium constant for:

2NO_2(g) ⇌ 2NO_(g) + O_2(g)

• 6.44 x 10⁵

• 1.55 x 10^-6

• 3.22 x 10⁵

What is the Kc expression for the following reaction:

MgCO3(s) + 2HCl(g) ⇌ MgCl2(s) + CO2(g) + H2O(l)?

•  $\frac{\left[CO_2\right]}{\left[HCl\right]}$  

•  
   $\frac{\left[MgCl_2\right]\left[CO_2\right]\left[H_2O\right]}{\left[HCl\right]^2\left[MgCO_3\right]}$  
  

•  $\frac{\left[CO_2\right]}{\left[HCl\right]^2}$  
  

•  $\frac{\left[CO_2\right]\left[H_2O\right]}{\left[HCl\right]^2}$  
  

C₂H₄(g) + 3 O₂(g) ⇌ 2CO₂(g) + 2H₂O(g)

An equal number of moles of each of the reactants is sealed in a container and allowed to come to the equilibrium shown above. At equilibrium which of the following must be true?

I. [CO₂] must be equal [H₂O]

II. [O₂] must be less than [C₂H₄]

III. [CO₂] must be greater than [C₂H₄]

• I only

• II only

• III only

• I and II

• II and III

CH₄(g) + CO₂(g) ⇌ 2 CO(g) + 2 H₂(g)

A 1.00-L flask is filled with 0.30 mol of CH₄ and 0.40 mol of CO₂, and allowed to come to equilibrium. At equilibrium, there are 0.20 mol of CO in the flask. What is the value of K_c, the equilibrium constant, for the reaction?

• 1.2

• 0.027

• 0.30

• 0.060

• 3.0

What is the equilibrium expression for:

Fe₃O₄(s) + 4 H₂(g) ⇌ 3 Fe(s) + 4 H₂O(g)

• K = ([Fe]³[H₂O]⁴ ) / ([Fe₃O₄][H₂]⁴)

• K = ([Fe₃O₄][H₂]⁴)/ ([Fe]³[H₂O]⁴)

• K = [H₂O]⁴ / [H₂]⁴

• K = [H₂]⁴ / [H₂O]⁴

H₂(g) + I₂(g) ⇄ 2 HI(g)

At 450^oC, 2.0 moles each of H₂(g), I₂(g), and HI(g) are combined in a 1.0 L rigid container. The value of K_c at

450^oC is 50. Which of the following will occur as the system moves toward equilibrium?

• More H₂(g) and I₂(g) will form.

• More HI(g) will form.

• The total pressure will decrease.

• No reaction will occur, because the number of molecules is the same on both sides of the equation.

For the reaction...

heat + N₂ + O₂ ⇌ 2NO

If NO is removed from the system, the concentration of N₂ will _______.

• increase

• decrease

• remain the same

• double

Which of the following is NOT true at equilibrium?

• The concentrations of reactants and products do not change.

• The forward and reverse reactions proceed at the same rate.

• The concentration of the reactants is equal to the concentration of the products.

• The forward and reverse reactions continue to occur.

Tags

NGSS.HS-PS1-6