Question

A sample of unknown pressure occupies 0.776L at a temperature of 298K. The sample of gas is then tested under known

conditions and has a pressure of 32.6 kPa and occupies 0.664L at 303K. What was the original pressure of the gas?

A. 27.43 kPa

B. 38.62 kPa

C. 58.73 kPa

D. 84.11 kPa

Answer 1

27.43 kPa (Option A)

Step-by-step explanation:

We can solve this by the use of the Ideal Gases Law.

P . V = n . R . T

As n and R are constant, we avoid them from the equation so:

P₁ . V₁ / T₁ = P₂ . V₂ / T₂

P₁ . 0776L / 298K = 32.6 kPa . 0.664L / 303K

P₁ . 0776L / 298K = 0.0714 kPa .L/K

P₁ . 0776L = 0.0714 kPa .L/K . 298K

P₁ = 21.289 kPa.L / 0.776L

P₁ = 27.43 kPa