In this solution we are having two components i.e. NaCl and H₂O. So the %age mass of NaCl is calculated by following formula,
%age mass of NaCl = (Mass of NaCl / Mass of NaCl + Mass of H₂O) × 100 ------ (1)
Calculating Mass of NaCl at 50°C;
Solubility of NaCl was searched online and was found 36.69 g / 100 mL of water at 50 °C.
Calculating Mass of 100 mL H₂O at 50°C;
Density of H₂O at 50 °C is 0.988 g/ml, so for 100 mL
As,
Density = Mass / Volume
Mass = Density × Volume
Mass = 0.988 g/mL × 100 mL
Mass = 98.8 g
Putting Masses of NaCl and H₂O in eq. 1,
%age mass of NaCl = (36.69 g / 36.69 g + 98.8 g) × 100
%age mass of NaCl = (36.69 g / 135.49 g) × 100
%age mass of NaCl = 27.07 %