Question

Calculate the [H⁺] in a 0.010 M solution of HCN, K_a = 6.2 × 10^–10. 

a) 1.0 × 10^–7 M 

b) 2.5 × 10^–6 M 

c) 3.6 × 10^–3 M 

d) 6.2 × 10^–10 M 

e) none of these

Answer 1

b) 2.5 × 10^–6 M