• question_answer $100\text{ }ml$ of $\frac{N}{10}HCl$ are mixed with 300 ml of $\frac{N}{20}$ $HN{{O}_{3}}$. The normality of the resulting solution will be A)  $\frac{N}{15}$                                           B)  $\frac{N}{20}$C)  $\frac{N}{16}$                                              D)  $\frac{N}{18}$

$100\text{ }ml$ of $\frac{N}{10}HCl=\frac{1}{100}g.$ $eq=0.01\,g\,\,eq$ $300\,\,ml$ of $\frac{N}{20}HN{{O}_{3}}=\frac{1}{20}\times \frac{1}{1000}\times 300$                 $=0.015\,g\,\,eq$ Total acid $=0.01+0.015$                 $=0.025\,\,geq.$                 $=\frac{1}{40}\,g\,\,eq.$ Total volume $=400\,ml$ $\therefore$   Normality  $=\frac{{\scriptstyle{}^{1}/{}_{40}}}{400}\times 1000=\frac{1}{16}$