Nitrogen gas (N₂) reacts with hydrogen gas (H₂) to form ammonia (NH₃). At 200°C in a closed container, 1.0 atm of nitrogen gas is mixed with 2.0 atm of hydrogen gas. At equilibrium, the total pressure is 1.9 atm. Calculate the partial pressure of hydrogen gas at equilibrium.

The partial pressure of hydrogen gas at equilibrium is 1.26 atm

Explanation:

Let's use the molar fraction to solve this:

Molar fraction = Moles of gas / Total moles

Molar fraction = Gas pressure / Total pressure

Without equilibrium, we can think that the total system pressure is the sum of the partial pressures of each gas.

1 atm N₂ + 2 atm H₂ = 3 atm

Molar fraction for H₂ = 2 atm / 3atm → 0.66

Let's replace the molar fraction in equilibrium

Gas pressure / 1.9 atm = 0.66

Gas pressure = 1.26atm