Question

Half a mole of helium at 27⁰C and at a pressure of 2 atmosphere is mixed with 1.5 mole of N₂ at 77⁰C and at a pressure at 5 atmosphere so that the volume of the mixture is equal to the sum of their initial volumes. If the temperature of the mixture is 69⁰C, its pressure in atmosphere is –

• A. 3.5
• B. 3.8
• C. 3.95
• D. 4.25

Answer 1

Answer: (B)

3.8

Answer 2

Apply V_mix = V₁ + V₂

Ž $\frac{T_{mix}}{P_{mix}} = \frac{T_{1}}{P_{1}} + \frac{T_{2}}{P_{2}}$