Gas Law Calculator

Solve problems for Ideal, Combined, and other gas laws.

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Worked Examples: Ideal and Combined Gas Laws

Example 1: Ideal Gas Law — Find n

Given P = 1.00 atm, V = 24.6 L, T = 298 K. R = 0.08206 L·atm·mol−1·K−1.

  1. Use PV = nRT → n = PV / RT.
  2. n = (1.00 × 24.6) / (0.08206 × 298) = 24.6 / 24.468 ≈ 1.01 mol.

Example 2: Combined Gas Law — Find P2

P1 = 0.980 atm, V1 = 2.00 L, T1 = 300 K → V2 = 3.50 L, T2 = 350 K, find P2.

  1. Use P1V1/T1 = P2V2/T2 → P2 = (P1V1T2)/(T1V2).
  2. Compute: (0.980×2.00×350)/(300×3.50) = 686 / 1050 = 0.653 atm.

Example 3: Charles’s Law — Find V2

V1 = 1.50 L at 20°C (293.15 K). Heat to 100°C (373.15 K), pressure constant. Find V2.

  1. V1/T1 = V2/T2 → V2 = V1(T2/T1).
  2. V2 = 1.50 × (373.15 / 293.15) = 1.50 × 1.273 ≈ 1.91 L.