Question

For the reaction Cu2S(s)⇌2Cu+(aq)+S2−(aq)Cu2S(s)⇌2Cu+(aq)+S2−(aq), the equilibrium concentrations are as follows: [Cu+]=1.0×10−5[Cu+]=1.0×10−5 M, [S2−]=1.0×10−2[S2−]=1.0×10−2 M. The equilibrium constant is:

Answer 1

1x10⁻¹²

Step-by-step explanation:

• Cu₂S(s) ⇌ 2Cu⁺(aq) + S²⁻(aq)

At equilibrium:

• [Cu⁺] = 1.0x10⁻⁵ M

• [S²⁻] = 1.0x10⁻² M

The equilibrium constant for the the reaction can be written as:

• Keq = [Cu⁺]² * [S²⁻]

[Cu⁺] is squared because it has a stoichiometric coefficient of 2 in the reaction. Cu₂S has no effect on the constant because it is a solid.

Now we can calculate the equilibrium constant:

• Keq = (1.0x10⁻⁵)² * 1.0x10⁻² = 1x10⁻¹²