Chemistry help?

Question

Discuss whether the value of K for the reac-on: HCN(aq) + F–(aq) CN–(aq) + HF(aq) is >1, <1, =1 (Ka for HCN is 6.2×10–10; Ka for HF is 7.2×10–4.) Explain your answer.

 

Answer 1

Step 1:

The chemical reaction is .

Consider that the reaction takes place in two elementary steps.

Reaction 1: .

Here acid ionization constant is .

Reaction 2: .

Here acid ionization constant is .

Step 2:

The chemical reaction is .

k_a for [HCN] is .

k_a for [HF] is .

Equilibrium constant :

Here .

If K < 1 then reverse reaction occurs.

Hence here reverse reaction takes place.

Solution:

Reverse reaction occurs.