Answer to Question #109399 in Chemistry for Denise Reyes

Question

How many grams of nitrogen do I have if a sample of the gas occupies a space of 4.1 liters at a pressure of 1.2 atm, and a temperature of 800 K.

Answer 1

Nitrogen gas: N₂;

Molar mass of N₂ = M_r(N₂) = 2*Ar(N) = 2*14 = 28 g/mol;

gas pressure: P = 1.2 atm;

gas volume: V = 4.1 L;

temperature: T = 800 K;

gas constant: R=0.082 L atm K⁻¹ mol⁻¹.

Solution:

Let's use the gas law, PV = nRT.

Rearrange the equation to isolate n and solve.

n = (PV) / (RT).

n = (1.2 * 4.1) / (0.082 * 800) = (0.075 moles).

Moles of N₂ = n(N₂) = 0.075 moles

Molar mass = grams / moles.

m(N₂) = M_r(N₂) * n(N₂) = (28 g/mol) * (0.075 moles) = 2.1 g.

m(N₂) = 2.1 g.

Answer: 2.1 grams of nitrogen (N₂).