Question

When nitrogen gas (N2) reacts with hydrogen gas(H) ammonia gas (NH3) is formed. How many grams of hydrogen gas are required to react
completely with 3.5 L of nitrogen at STP? Show your work for full credit.

Answer 1

Mass of Hydrogen gas required to react : 0.936 g

Further explanation

Reaction on Nitrogen gas and Hydrogen gas to produce Ammonia gas

N₂ (g) + 3 H₂ (g) ⇒ 2 NH₃ (g)

Conditions at T 0 ° C and P 1 atm are stated by STP (Standard Temperature and Pressure). At STP, Vm is 22.4 liters / mol

so mol Nitrogen for 3.5 L at STP :

$\tt mol=\dfrac{3.5~L}{22.4~L}=0.156$

From the equation, mol ratio of N₂ : H₂ = 1 : 3, so mol H₂ :

$\tt \dfrac{3}{1}\times 0.156=0.468$

then mass of Hydrogen(MW= 2 g/mol) :

$\tt mass=mol\times MW\\\\mass=0.468\times 2\\\\mass=0.936~g$