List of top Zoology Questions on pH value

The pKa of a buffer solution with pH of 5, consisting of 0.4 M sodium acetate and 0.04 M acetic acid, is ____. (Answer in integer)
Based on the context given below, answer the following questions:
Glycine is most often used as a buffering agent in biochemical experiments. This diprotic amino acid has a pKa value of 2.4 owing to carboxyl group and 9.6 owing to amino group. Glycine can exist as a zwitterion which can exist in either protonated form\((NH^+_3 )\) or as a free base \((-NH_2)\)because of the reversible reaction: 
Glycine is most often used as a buffering agent
The pH of cytoplasm and lysosomes are ~ 7 and ~5 respectively. How many fold H+ ion concentration is higher in lysosomes compared to cytoplasm?