NCERT Class 12 Chemistry Chapter 2 Solutions Quiz

Mass Percentage Calculations

• Mass percentage of a component in a solution is calculated as:
  [ \text{Mass %} = \left( \frac{\text{mass of component}}{\text{total mass of solution}} \right) \times 100 ]

• For benzene (C6H6):
  Mass of benzene = 22 g
  Mass of carbon tetrachloride (CCl4) = 122 g
  Total mass of solution = 22 g + 122 g = 144 g
  Mass percentage of benzene:
  [ \text{Mass % of C6H6} = \left( \frac{22 , \text{g}}{144 , \text{g}} \right) \times 100 \approx 15.28% ]

• For carbon tetrachloride (CCl4):
  Mass percentage of CCl4:
  [ \text{Mass % of CCl4} = \left( \frac{122 , \text{g}}{144 , \text{g}} \right) \times 100 \approx 84.72% ]

Molar Mass

• Molar mass of benzene (C6H6):
  Carbon (C) = 12.01 g/mol, Hydrogen (H) = 1.008 g/mol
  Molar mass calculation:
  [ (6 \times 12.01) + (6 \times 1.008) = 72.06 + 6.048 = 78.11 , \text{g/mol} ]

• Molar mass of carbon tetrachloride (CCl4):
  Chlorine (Cl) = 35.45 g/mol
  Molar mass calculation:
  [ 12.01 + (4 \times 35.45) = 12.01 + 141.80 = 153.81 , \text{g/mol} ]

Solution Summary

• Total mass of the solution when 22 g of benzene is mixed with 122 g of carbon tetrachloride is 144 g.
• Mass percentages provide insight into the composition of the solution, with benzene making up approximately 15.28% and carbon tetrachloride about 84.72%.