Answer to Question #112910 in General Chemistry for Jillian duvol

Question

Let's say we have a mixture of h2 and o2. The mixture contained 6.7 hydrogen gas and 3.3 mols of oxygen gas. The mixture is in 300 l container at 273 Kelvin and total pressure of the gas mixture is 0.75atm. What is the partial pressure of each gas

Answer 1

The partial pressure of each gas in a mixture of H₂ and O₂ is proportional to its mole fraction. As a result:

n_x / n_t = p_x / p_t

where nx - number of moles of gas, nt - number of moles of a mixture, px - partial pressure of gas, pt - total pressure of mixture.

From here:

p_x = n_x × p_t / n_t

Here, p_t = 0.75 atm and n_t = n(H₂) + n(O₂) = 6.7 mol + 3.3 mol = 10 mol

p(H₂) = n(H₂) × p_t / n_t = 6.7 mol × 0.75 atm / 10 mol = 0.50 atm

p(O2) = n(O₂) × p_t / n_t = 3.3 mol × 0.75 atm / 10 mol = 0.25 atm

Answer: p(H₂) = 0.50 atm, p(O₂) = 0.25 atm