calculate the pH of an aqueous solution of 0.1 M ammonium formate assuming complete dissociation.pkb for formic acid=3.8,and pkb of ammonia=4.8?

When it comes to Ammonium formate, it is the perfect blend of weak base and weak acid.  According to the pH formula, we need to substitute the values.  When we place the values, we can get the following equation.  The given conditions are the pka of formic acid = 3.8 and pkb of ammonia = 4.8

ph=1/2pkw + 1/2pka -1/2pkb

=1/2×14 + 1/2×3.8 -1/2×4.8

pH=6.5.