Following solutions were prepared by mixing
different volumes of NaOH and HCl of different
concentrations :
a. 60mL ``\frac{M}{10}``HCl +
40mL ``\frac{M}{10}`` NaOH
b. 55mL ``\frac{M}{10}``HCl +
45mL ``\frac{M}{10}`` NaOH
c. 75mL ``\frac{M}{5}``HCl +
25mL ``\frac{M}{5}`` NaOH
d. 100mL ``\frac{M}{10}``HCl +
100mL ``\frac{M}{10}`` NaOH
pH of which one of them will be equal to 1 ?
(1) b
(2) a
(3) d
(4) c