Question

Calculate mole fraction of hcl in solution of hcl containing 24.8% of hcl by maas

Answer 1

Given,

Amount of HCl by mass = 24.8%

Let us consider that the total mass of the solution = 100 g

So, given mass of HCl = 24.8 g

and, mass of H₂O = (100 - 24.8) g = 75.2 g

Now,

Number of moles of HCl , n₁ = $\frac{Given mass of HCl}{Molecular mass of HCl}$

                                         = $\frac{24.8 g}{36.5 g}$

                                         = 0.67 moles

Number of moles of H₂O, n₂ = $\frac{Given mass of H₂O}{Molecular mass of H₂O}$

                                         = $\frac{75.2 g}{18 g}$

                                         = 4.17 moles

∴ Mole fraction of HCl in solution = $\frac{n₁}{n₁ + n₂}$

                                                       = $\frac{0.67}{0.67 + 4.17}$

                                                       = 0.14