Question

A buffer of pH 9.26 is made by dissolving x moles of ammonium sulfate and 0.1 mole of ammonia into a 100 ml solution. If pKa of ammonia is 4.74, calculate the value of x.
a) 0.032 moles
b) 0.100 moles
c) 0.268 moles
d) 0.536 moles