CHEMICAL EQUILIBRIUM

Calculate the equilibrium constant (Kc) for the given reaction

N₂ (g) + 3H₂ (g) ↔ 2NH₃ (g)

At equilibrium [N₂] = 0.34 M, [H₂] = 0.13 M, and [NH₃] = 0.19 M.

• 48

• 33

• 48.0

• 33.07

Calculate the equilibrium constant (Kc) for the given reaction and tell whether equilibrium lies to the left or the right.

2NO (g) + Br₂ (g) ↔ 2NOBr (g)

At equilibrium [NO] = 0.5 M, [Br₂] = 0.25 M, and [NOBr] = 3.5 M.

• 56 lies to the right

• 200 lies to the right

• 196 lies to the left

• 56 lies to the left

Calculate the equilibrium constant (Kc) for the given reaction and tell whether equilibrium lies to the left or the right.

PCl₅ (g) ↔ PCl₃ (g) + Cl₂ (g)

Equilibrium concentrations are: [PCl₅] = 0.25 M, [PCl₃] = 9.7 × 10^-4 M, and [Cl₂] = 3.2 × 10^-3 M.

• 1.02 lies to the left

• 0.000012 lies to the left

• 1.02 lies to the right

• 0.000012416 lies to the left

A mixture of 0.500 mol H₂ and 0.500 mol I₂ was placed in a 1.00L stainless-steel flask at 430⁰C. The equilibrium constant Kc for the reaction H₂ (g) + I₂ ↔ 2HI (g) is 54.3 at this temperature. Calculate the concentrations of H₂, I₂ , and HI at equilibrium.

Use ICE Table

• [H₂] = 0.107 M

  [I₂] = 0.107 M

  [HI] = 0.768 M

• [H₂] = 0.768 M

  [I₂] = 0.107 M

  [HI] = 0.107 M

• [H₂] = 0.107 M

  [I₂] = 0.768 M

  [HI] = 0.107 M

• [H₂] = 0.107 M

  [I₂] = 0.107 M

  [HI] = 0.0768 M

Tags

NGSS.HS-PS1-5

The equilibrium constant (Kc) for the formation of nitrosyl chloride, an orange-yellow compound, from nitric oxide and molecular chlorine is 6.5 x 10 ⁴ at 35 ⁰ C. In a certain experiment, 2.0 x 10 ^-2 mole of NO, 8.3 x10 ^-3 mole of Cl₂, and 6.8 moles of NOCL are mixed in a 2.0-L flask.

2NO(g) + Cl₂ ↔ 2NOCl (g)

Find Q and predict how the reaction will proceed.

• 2.9 x 10 ⁷ to the left

• 3.0 x 10 ⁷ to the left

• 2.89 x 10 ⁷ to the right

• 2.89 x 10 ⁵ to the left

Tags

NGSS.HS-PS1-2

NGSS.HS-PS1-5

Consider the following system at equilibrium:

CH₄(g) + 2H₂O (g) ↔ CO₂ (g) + 4H₂O (g)

Suppose the concentration of CH₄ decreased, in which direction does the reaction shift to reestablish equilibrium?

• The reaction shifts to the left

• The reaction shifts to the right

Tags

NGSS.HS-PS1-5

NGSS.HS-PS1-6

Consider the following system at equilibrium:

CH₄(g) + 2H₂O (g) ↔ CO₂ (g) + 4H₂ (g)

Suppose the concentration of CH₄ decreased, what happens to the concentrations of H₂O, CO_2, and H₂ as the reaction shifts to reestablish equilibrium?

• The concentrations of the products, CO_2, and H₂ will decrease and the reactant H₂O, will increase in concentration.

• The concentrations of the products, CO_2, and H₂ will increase and the reactant H₂O, will decrease in concentration.

Tags

NGSS.HS-PS1-5

Predict whether the reaction will shift to the right, left or not be affected by an INCREASE in temperature

2H₂O₂ (g) ↔ 2H₂O (g) + O₂ (g) exothermic

• left

• right

• no effect

Tags

NGSS.HS-PS1-5

Predict whether the reaction will shift to the right, left or not be affected by an INCREASE in temperature

2H₂O₂ (g) ↔ 2H₂O (g) + O₂ (g) endothermic

• left

• right

• no effect

Tags

NGSS.HS-PS1-5

What is the K_c expression for this reaction?    2 NO_(g)  +  O_2(g) ⇌  2 NO_2(g)

• K_c = [NO₂]² / [NO]² [O₂]

• K_c =  [NO]² [O₂] / [NO₂]²

• K_c = [NO]² [O₂] [NO₂]²

• K_c = [NO₂]² / [NO]² +  [O₂]