Question

The molarity of hcl solution by dissolving 4.6g of it in 250 ml water is

Answer 1

$\mathfrak{\large{\underline{\underline{Answer:-}}}}$

$\mathfrak{\large{\underline{\underline{Given :-}}}}$

Mass of HCl is = 4.6 g

Volume of water = 250 ml

$\mathfrak{\large{\underline{\underline{</strong><strong>S</strong><strong>o</strong><strong>l</strong><strong>u</strong><strong>t</strong><strong>i</strong><strong>o</strong><strong>n</strong><strong>:-}}}}$

Molarity is defined as number of moles present per l of solution.

$\bold{</strong><strong>N</strong><strong>o</strong><strong> </strong><strong>.</strong><strong> </strong><strong>of</strong><strong> </strong><strong>moles</strong><strong> </strong><strong>of</strong><strong> </strong><strong>HCl</strong><strong> </strong><strong>=</strong><strong>\frac{given \: mass}{formula \: mass} </strong><strong> </strong><strong>}$

No. of moles of HCl = $\bold{</strong><strong> \frac{4.6}{36.5} </strong><strong> }$

No. of moles of HCl = 0.12 mol

Now, we can use formula of molarity :-

★ $\boxed{\sf{ </strong><strong>Molarity</strong><strong> </strong><strong>=</strong><strong> </strong><strong>\frac{no. \: of \: moles \: of \: </strong><strong>HCl</strong><strong>}{volume \:o f\:solution \: } </strong><strong>}}$

$\implies$ Molarity = $\bold{</strong><strong> \frac{0.12}{250} \times 1000</strong><strong>}$

$\implies$ Molarity = $\bold{</strong><strong>0</strong><strong>.</strong><strong>1</strong><strong>2</strong><strong> </strong><strong>×</strong><strong> </strong><strong>4</strong><strong>}$

$\implies$ Molarity = $\bold{</strong><strong>0</strong><strong>.</strong><strong>4</strong><strong>8</strong><strong>}$

hence, the molarity of 250 ml of HCl is 0.48M.