Question

A sample of concentrated HCL acid is 11.8M HCL and has a density of 1.190g/cm-cubed. Calculate: Mass fraction, Molality and Mole fraction.

Answer 1

$\frac{11.8mol_{ HCl}}{L_{solution}}=\frac{mol_{HCL}}{Kg_{H_2O}}$

$\frac{1.190g_{solution}}{1ml_{solution}}×1000ml=1190g_{solution}$

$11.8mol×36.5=430.7g$

Mass $=1190-430.7=759.3grams$

Mole fraction$=\frac{759.3}{1190}=0.638$