AP Chemistry Q4 Extra Credit

Given the K_c for a forward reaction, how can you find K_c for the reverse reaction?

• Divide K_c by 1

• Divide 1 by K_c

• Square K_c

• Take the square root of K_c

This endothermic reaction is at equilibrium.

If its temperature is increased (at constant volume and pressure), which way will the equilibrium shift?

• To products (right)

• To reactants (left)

For the reaction...

SO₂ + O₂ <−> SO₃

If the concentration of SO₂ is increased, the system will shift ___________.

• left

• right

• left and right

• neither left nor right

For the reaction...

heat + N₂ + O₂ ↔ 2NO

If heat is added to the chemical system, the system will shift _______.

• left

• right

• left and right

• neither left nor right

2SO₂ (g) + O₂ (g) ⇌ 2SO₃ (g)

Decreasing the volume of container will

• shift the system right

• shift the system left

• change K

• have no effect

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

• increase
• decrease
• remain the same
• double

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]

An equilibrium constant with a large value, e.g. K_c = 1000, indicates…

• A very fast reaction
• Mostly products at equilibrium
• Mostly reactants at equilibrium
• Nothing useful at all

Which is true for a system at equilibrium?

• Forward reaction rate is faster than the reverse and concentrations are equal

• Forward and reverse reaction rates are equal and concentrations are constant

• Forward and reverse reaction rates are equal and concentrations are equal

• Forward reaction rate is faster than the reverse and concentrations are constant

What is [H₂O] if K = 1.2,
[CO₂] = 0.846M, & [CH₄]= 0.0713M?
4CuO_(s)+CH_4(g)↔CO_2(g)+4Cu_(s) +2H₂O_(g)

• 0.101 M
• 0.318 M
• 0.0102 M
• 3.77 M