Practicing Success

Target Exam

CUET

Subject

Chemistry

Chapter

Physical: Solutions

Question:

What is the amount of solute (molar mass = 60 g/mol) that must be added to 180 g of water so that the vapour pressure of water is lowered by 10%?

Options:

30 g

60 g

120 g

12 g

Correct Answer:

60 g

Explanation:

\(\frac{Po - P}{Po}\) = \(\frac{Wb × Ma}{Wa × Mb}\)

\(\frac{10}{100}\) = \(\frac{Wb × 18}{180 × 60}\)

Wb = \(\frac{10}{100}\) x \(\frac{180 × 60}{18}\) = 60 g