Equilibrium Y13 OCR A

Which is the reactant - and why?

• A, as concentration decreases
• B, as concentration decreases
• A, as concentration increases
• B, as concentration increases

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]

If the equilibrium constant is much greater than one (K >> 1) then

• Equilibrium is not established.
• Equilibrium lies to the right (products are favored)
• Equilibrium lies to the left (reactants are favored)
• Neither products or reactants are favored.

If the equilibrium constant is much less than one (K << 1) then

• Equilibrium is not established.
• Equilibrium lies to the right (products are favored)
• Equilibrium lies to the left (reactants are favored)
• Neither products or reactants are favored.

Which of the following is true about chemical reaction at equilibrium

• only the forward reaction stops

• only the reverse reaction stops

• both forward and reverse reactions stop

• the rate constants for the forward and reverse reactions are equal

• the rates of the forward and reverse reactions are equal

Which of the following is true regarding the concentration of the products, for a chemical reaction that is already at equilibrium, assuming no disruptions to the equilibrium?

• the concentrations of products will not change because there are no more products

• the concentrations of products will not change because the limiting reactant is gone

• the concentrations of products will not change because the forward and reverse rates are equal

• the concentrations of products will change continually because of reversibility

The sum of all the ρP is the

Answer explanation

5.1.2(a)

Liquids and solids should be omitted from K expressions in the case of _____________ equilibria

Answer explanation

5.1.2(d)

Which equilibrium constants would be appropriate for this system?

A(g) + B(g) ⇌ 2C(g)

• K_c

• K_p

• K_w

Answer explanation

5.1.2(d)

Which equilibrium constant/s would be appropriate for this system?

A(aq) ⇌ B(aq) + H₂O(l) + C(s)

• K_c

• K_p

• K_w

Answer explanation

5.1.2(d)