How many moles of HCOONa must be added to 1L of 0.1 M HCOOH to prepare a buffer solution with a pH o — Ionic Equilibrium Chemistry Question

💡 Solution & Explanation

HCOOH and HCOONa forms acidic Buffer Using Henderson – Hasselbalch equation, we have a Conjugate base pH = pK log Acid As the final volume of both conjugate base and acid in buffer solution will be same, we can replace concentration with no. of moles, Thus, a no. of moles of conjugate base pH = pK log no. of moles of acid a moles of HCOO pH = pK log 0.1 moles of HCOOH >> moles of HCOO 3.4 = 3.7 log 0.1 >> moles of HCOO 0.3 = log 0.1 >> 0.3 0.1 10 moles of HCOO >> 0.3 0.1 0.1 moles of HCOO 0.05 2 10 >>