Question

Henry’s law constant of oxygen is 1.4 × 10^–3 mol lit^–1 atm^–1 at 298 K. How much of oxygen is dissolved in 100 ml at 298 K when the partial pressure of oxygen is 0.5 atm?

Options

• 1.4 g

• 3.2 g

• 22.4 mg

• 2.24 mg

Answer 1

2.24 mg

Explanation:

According to Henry's law,

solubility = k × p

= 1.4 × 10^–3 × 0.5 mol/L

= 7 × 10^–4 mol/L

Number of moles in 100 mL = 7 × 10^–5

Mass of oxygen (m) = 7 × 10^–5 × 32 g = 2.24 mg