Question

Calculate the pressure in atm of .68 mol of H at 298K and occupying 4.5 L

Answer 1

3.7 atm

General Formulas and Concepts:

Atomic Structure

• Moles

Gas Laws

Ideal Gas Law: PV = nRT

• P is pressure
• V is volume
• n is number of moles
• R is gas constant
• T is temperature

Step-by-step explanation:

Step 1: Define

Identify variables

[Given] n = 0.68 mol H

[Given] T = 298 K

[Given] V = 4.5 L

[Given] R = 0.0821 L · atm · mol⁻¹ · K⁻¹

[Solve] P

Step 2: Find Pressure

1. Substitute in variables [Ideal Gas Law]: P(4.5 L) = (0.68 mol)(0.0821 L · atm · mol⁻¹ · K⁻¹)(298 K)
2. Multiply [Cancel out units]: P(4.5 L) = (0.055828 L · atm · K⁻¹)(298 K)
3. Multiply [Cancel out units]: P(4.5 L) = 16.6367 L · atm
4. Isolate P [Cancel out units]: P = 3.69705 atm

Step 3: Check

Follow sig fig rules and round. We are given 2 sig figs as our lowest.

3.69705 atm ≈ 3.7 atm