The pH of a solution formed by mixing 50 ml of M HCl and 30 mL of M NaOH is\

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Professor PC Thomas Classes · Answer

20 ml M HCl is in excess in a total volume of 80 ml . $$ \begin{aligned} & \begin{aligned} & 	herefore\left[\mathrm{H}^{+}ight]= \frac{20 	imes 1}{80} \mathrm{M}=\frac{1}{4}=0.25=2.5 	imes 10^{-1} \ & \mathrm{pH}=-\log \left[\mathrm{H}^{+}ight]=-\log 2.5 	imes 10^{-1} \ &=-\log 10^{-1}-\log 2.5=1-0.4=0.6 \end{aligned} \ & \mathrm{pH}=-\log 0.25=-(-1+0.3979)=0.6021 \end{aligned} $$