Q1 / 125 · BITSAT 2013 · Chemistry

How many grams of concentrated nitric acid solution should be used to prepare $250 \mathrm{~mL}$ of $2.0 \mathrm{MHNO}_{3} ?$ The concentrated acid is $70 \% \mathrm{HNO}_{3}$

  • A
    $90.0 \mathrm{~g}$ conc. $\mathrm{HNO}_{3}$
  • B
    $70.0 \mathrm{~g}$ conc. $\mathrm{HNO}_{3}$
  • C
    $54.0 \mathrm{~g}$ conc. $\mathrm{HNO}_{3}$
  • Correct answer
    D
    $45.0 \mathrm{~g}$ conc. $\mathrm{HNO}_{3}$

Solution

$\quad$ Molarity $(\mathrm{M})=\frac{\mathrm{wt} \times 1000}{\text { mol. wt. } \times \mathrm{vol}(\mathrm{mL})}$ $2=\frac{\mathrm{wt} .}{63} \times \frac{1000}{250}$ $\mathrm{wt}=\frac{63}{2} \mathrm{~g}$ wt. of $70 \%$ acid $=\frac{100}{70} \times 31.5=45 \mathrm{~g}$

Hence, the correct answer is option: 'D'.

Relevant Questions