Question

When solid ammonium chloride dissociates at a certain temperature in a 0.500dm3 container, ammonia and hydrogen chloride are formed

NH4Cl --> NH3 + HCl

The initial amount of ammonium chloride was 1.00mol, and when the system had reached equilibrium there was a 0.300mol of ammonium chloride

What is the numerical value of Kc for this reaction under these conditions?

Answer 1

Answer on Question #71075, Chemistry / General Chemistry

Question:

When solid ammonium chloride dissociates at a certain temperature in a 0.500 dm³ container, ammonia and hydrogen chloride are formed:

NH₄Cl --> NH₃ + HCl

The initial amount of ammonium chloride was 1.00 mol, and when the system had reached equilibrium there was a 0.300 mol of ammonium chloride.

What is the numerical value of $K_{c}$ for this reaction under these conditions?

Solution:

Amount of dissociated ammonium chloride: 0.700 mol

Concentration of ammonia: [NH₃] = 0.700mol / 0.500dm³ = 1.4 mol/dm³

Concentration of hydrogen chloride: [HCl] = 0.700mol / 0.500dm³ = 1.4 mol/dm³

Assume that mixture of gases is ideal gas:

$K_{c} = [NH_{3}] \cdot [HCl] = 1.4 \cdot 1.4 = 1.96$

Answer:

$K_{c} = 1.96$