Question

Solve this please . ​

Answer 1

$\huge\mathbb{\blue{QUESTION-}}$

How many grams of concentrated nitric acid solution should be used to prepare 250mL of 2.0M $\sf{HNO_3}$ ? The concentrated acid is 70% $\sf{HNO_3}$.

$\Huge\mathbb{\blue{SOLUTION-}}$

Given ,

❏ Molarity of solution = 2

Volume of solution = 250mL

⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀= ${\sf \dfrac{250}{1000}}$

⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀

❏ Molar Mass of $\bf{HNO_3}$

= 1 + 14 + 3 × 16

= 63 $\sf{gmol^{-1}}$

${\sf Molarity=\dfrac{Weight\:Of\:HNO_3}{Mass\:of\:HNO_3 × Volume\:Of\:Solution}}$

$\implies{\sf Weight \: of \: HNO_3 = Molarity × Mol. mass × Volume }$

$\implies{\sf 2×63×\dfrac{1}{4} }$

$\implies{\sf 31.5\:g}$

${\sf It \: is \: the \: weight\: of \: 100\% \; HNO_3}$

${\sf But \: the \: given \: acid \: is \: 70\% \: HNO_3}$

⛬ Its weight = 31.5 × ${\sf \dfrac{100}{70}g}$

⠀⠀⠀⠀⠀⠀⠀⠀= ${\bf \red{45g}}$

$\Huge\mathbb{\blue{ANSWER-}}$

The concentrated acid is 70% $\sf{HNO_3}$ is ${\bf \red{45g}}$