Equilibrium Expressions

At what time the reaction reached equilibrium?

• t₁
• t₂
• t₃
• t₄

Identify the labels (a) and (b) on the graph.

• a is concentration of reactants and b is the concentration of product
• a is concentration of product and b is the concentration of reactant
• a is the volume of reactants and b is the volume of product
• a the mass of reactants and b is the mass of product

Tags

NGSS.HS-PS1-5

Define chemical equilibrium.

• A reaction is reversible.
• The concentration of the reactants is equal to the concentration of the products.
• The rate of a forward reaction is equal to the rate of the reverse reaction.
• The reaction stops and no further change in concentration occurs.

Which of the two graphs reaches equilibrium?

• The left one.
• The right one.
• Both of them.
• Neither.

Which of the following is NOT true at equilibrium?

• The forward and reverse reactions proceed at the same rate.
• The concentrations of reactants and products do not change.
• The concentration of the reactants is equal to the concentration of the products.
• The forward and reverse reactions continue to occur.

For the reaction...
N₂  +  O₂  <=>  2NO
If  O₂ is removed, the  concentration of N₂ will _______.

• increase
• decrease
• remain the same
• double

Tags

NGSS.HS-PS1-5

For the reaction...
SO₂ + O₂ <=>  SO₃
If the equilibrium position shifts to the right, the concentration of O₂ will ___________.

• increase
• decrease
• remain the same
• double

For the reaction...
N_{2 (g)} +  3 H_2 (g) <=> 2 NH_{3 (g)}

If the pressure in the system is increased,  which substance(s) will increase in concentration?

• N₂  (as 2 mol gas  → 4 mol gas)
• H₂ (as 2 mol gas  → 4 mol gas)
• N₂ and H₂ (as 2 mol gas  → 4 mol gas)
• NH₃ (as 4 mol gas  → 2 mol gas)

Tags

NGSS.HS-PS1-5

For the reaction...
N₂  +  O₂  <=>  2NO:  Δ H = +182 kJ mol^-1.
If the temperature is increased the equilibrium position will shift _______.

• to the left
• to the right
• to the left and right
• neither left nor right

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]