Question

An ammonia-ammonium chloride buffer, pH = 9. Concentration of ammonia = 0.25M. By how much the pH will change if 75ml 0.1M KOH be added to 200ml buffer solution. Kb = 2 x 10 -5

Answer 1

We know that , Ph= Pkb + log [ salt / base] Ph = 2×10^-5 log[ 200×0.25/75×0.1] Ph= 2×10^-5 × 0.82 Change in ph = 0.00064