Question

A 1 liter solution contains 0.357 M ammonium chloride and 0.268 M ammonia. Addition of 0.295 moles of hydrochloric acid will: (Assume that the volume does not change upon the addition of hydrochloric acid.) Raise the pH slightly Lower the pH slightly Raise the pH by several units Lower the pH by several units Not change the pH Exceed the buffer capacity

Answer 1

Initially:
Mol of NH4Cl = 0.357 mol
Mol of NH3 = 0.268 mol

We are adding 0.295 mol of HCl.
This added HCl will react with all of NH3.
Hence buffer capacity is lost and there are extra HCl which will raise the pH by several units

Answer: Raise the pH by several units