3.65 g of HCl is dissolved in 16.2 g of water, then the correct statement is / are

detailed solution

Correct option is D

Amount of HCl, $w=3.65g$

Amount of water ,$\text{W}\text{=}\text{16}\text{.2}\text{g}$

Molar mass of HCl (MW) = 36.5 g/mol

Molar mass of ${\text{H}}_{\text{2}}\text{O}$ $=18.02\text{g}/\text{mol}$

i)  Number of moles of HCl will find as follows:

                                       ${\text{n}}_{\text{HCl}}=\frac{\text{mass of HC}l}{\text{MW of HC}l}$

                                               $=\frac{3.65\text{ g}}{36.5\text{ g/mol}}=0.1\text{ mol}$

ii) Number of moles of${\text{H}}_{\text{2}}\text{O}$ :

                                         ${\text{n}}_{{\text{H}}_{\text{2}}\text{O}}=\frac{{\text{mass of H}}_{\text{2}}\text{O}}{{\text{MW of H}}_{\text{2}}\text{O}}$

                                        $\text{=}\frac{16.2\text{ g}}{18.02\text{g/mol}}=0.90\text{mol}$

    

iii) Mole fraction of HCl is calculated as follows:

     ${\text{X}}_{\text{HC}l}=\frac{\text{no}\text{. of moles of HC}l}{\text{no}\text{. of moles of HC}l\text{ + no}{\text{.of mols of H}}_2\text{O}}$

      ${\text{X}}_{HCl}=\frac{0.1}{0.1+0.9}=0.1$

iv) Mole fraction of ${\text{H}}_{\text{2}}\text{O}$ :

${\text{X}}_{{\text{H}}_{\text{2}}\text{O}}=\frac{\text{no}{\text{. of moles of H}}_2\text{O}}{\text{no}{\text{. of moles of H}}_2\text{O + no}\text{.of mols of HC}l}$

${\text{X}}_{{\text{H}}_{\text{2}}\text{O}}=\frac{0.90}{0.90+0.10}=0.90$

Hence, for given question all four answers are correct.