Question

The solubility of nitrogen gas in water at 25°C and a nitrogen pressure of 522 mm Hg is 4.7 × 10⁻⁴ mol/L. What is the value of the Henry's law constant in mol L⁻¹• atm⁻¹?

A. 9.0 x 10⁷ mol/L atm
B. 3.2 x 10⁻⁴ mol/L atm
C. 4.7 x 10⁻⁴ mol/L atm
D. 6.8 x 10⁻⁴ mol/L atm
E. 1.5 x 10³ mol/L atm

Answer 1

D. 6.8 x 10⁻⁴ mol/L atm

Step-by-step explanation:

Henry's Law states that:

S = kH * P

Where S is the solubility of a gas (in mol/L), kH is Henry's constant (in mol• L⁻¹• atm⁻¹) and P is the partial pressure of said gas (in atm).

The problem gives us S and P, while asking us to calculate kH:

• First we convert 522 mmHg into atm:

• 522/760 = 0.687 atm

Now we solve for kH:

4.7 × 10⁻⁴ mol/L = kH * 0.687 atm

• kH = 6.84x10⁻⁴ mol • L⁻¹• atm⁻¹