How many grams of NaOH is to be added to one litre of ` 1 M H_2CO_3` to get a `HCO_3^(-) //CO_3^(-2) ` buffer of maximum capacity ?

Options

A. 90 gram
B. 60 gram
C. 20 gram
D. 50 gram

Answer

B

Explanation

Buffer of max capacity `rArr [HCO_3^(-) ]= [CO_3^(2-) ]`
` rArr H_2CO_3` was neutralized and `HCO_3^(-) ` was `1//2` neutralized
i.e., NaOH required `= 1xx 1 + 1 xx (1)/(2) = (3)/(2) " moles weight " = 40 xx (3)/(2) = 60 gms `