$[$પાણીનો આયનીય ગુણાકાર $ = 1 \times {10^{ - 14}}]$
$(a)\;\;60\; \mathrm{mL} \frac{\mathrm{M}}{10}\; \mathrm{HCl}+40 \;\mathrm{mL} \frac{\mathrm{M}}{10} \;\mathrm{NaOH}$
$(b)\;\;55\; \mathrm{mL} \frac{\mathrm{M}}{10}\; \mathrm{HCl}+45 \;\mathrm{mL} \frac{\mathrm{M}}{10} \;\mathrm{NaOH}$
$(c)\;\;75\; \mathrm{mL} \frac{\mathrm{M}}{5}\; \mathrm{HCl}+25 \;\mathrm{mL} \frac{\mathrm{M}}{5} \;\mathrm{NaOH}$
$(d)\;\;100\; \mathrm{mL} \frac{\mathrm{M}}{10}\; \mathrm{HCl}+100 \;\mathrm{mL} \frac{\mathrm{M}}{10} \;\mathrm{NaOH}$
તેઓ પૈકી કોની $pH$ $1$ ને સમાન થશે ?