Chemical Equilibrium

What is true about irreversible reaction?

• It has limiting reactant

• It does not go to completion

• It always have two reactants

• the reaction equation is shown by double arrow

Which one is not characteristic of dynamic equilibrium?

• Reversible reaction

• Must be in closed system

• Amount of products similar to amount of reactants

• Rate of forward reaction equals to the rate of reverse reaction

In a reversible reaction,the reactants are kept in a closed jar. What happens when the lid of jar is removed?

• Dynamic equilbrium occurs

• Reaction reaches equilibrium

• Products are converted to reactants

• Rate of forward is no longer equals to rate of reverse reaction

In dynamic equilibrium,...............

• Change in energy does not occur

• No reactants are left at the end of reaction

• There is no exchange of matter

• Identity of reactants change

The following statements about the reaction is true except:

NH₂COONH₄(s) ⇌ CO₂(g) + 2NH₃(g)

• K_c = [CO₂][NH₃]²

• K_c = mol³L^-9

• it achieves homogenous equilibrium

• pure solid is not included in Kc expression

CH₃COOH(l) + CH₃OH(l) ⇌ CH₃COOCH₃(l) + H₂O(l)

What is the unit of its Kc?

• no unit

• mol³L^-9

• mol³L^-3

• molL^-1

The equilibrium constant, K_c for the chemical reaction below is 0.014 M at 900°C.

C(s) + CO₂(g) ⇌ 2CO(g)

Determine the value of K_p for the above reaction at the same temperature.

• 1.35 atm

• 0.014 atm

• 0.742 atm

• 1.00 atm

What is the value of K_p for 2CO(g) ⇌ C(s) + CO₂(g) at the same temperature if the Kp for the reverse reaction is 1.35 atm?

• 1.00 atm^-1

• 0.742 atm^-1

• 1.35 atm^-1

• 0.005 atm^-1

The equilibrium constant, K_p for the reaction below is 60.6 atm at 100°C.

2NOBr(g) ⇌ 2NO(g) + Br₂(g)

1.21 mol of NOBr, 0.86 mol of NO and 1.56 mol of Br₂ were found at a particular time and the total pressure was 111.15 atm in a 1.0 L vessel.

Determine the Q_p.

• 25.28 atm

• 24.13 atm

• 25.40 atm

• 27.00 atm

2 mol of ethanoic acid, CH₃COOH, is mixed with 2 mol of ethanol, CH₃CH₂OH in a 1L closed flask and allowed to achieve equilibrium in room temperature. The equilibrium mixture was found to contain 0.80 mol of ethyl ethanoate, CH₃COOCH₂CH₃.

CH₃COOH(l) + CH₃CH₂OH(l) ⇌ CH₃COOCH₂CH₃(l) + H₂O(l)

Calculate K_c for the above equilibrium at room temperature.

• 0.31

• 0.20

• 0.10

• 0.44