In an acidic buffer solution, if some `H_(2)So_(4)` is added, its `pH` will

Options

A. Remain constant
B. Change but cannot be predicted
C. Decrease
D. Increase

Answer

C

Explanation

Rule `(A A A):` In acid buffer `(A)`, on addition of `S_(A)(A)`, the concentration of `W_(A)(A)` increases and that of salt decreases, so `pH` decreases.
`pH = pK_(a) +"log"(["Salt" -x])/(["Acid" + x])`
`(x` is the concentartion of `H_(2)SO_(4)` added)