A 20 litre container at 400 K contains CO2(g) at pressure 0.4 atm and an excess of SrO (neglect the volume of solid SrO). The volume of the container is now decreased by moving the movable piston fitted in the container. The maximum volume of the container, when pressure of CO2 attains its maximum value, will be (Given that : SrCO3(s) SrO(s) + CO2(g), Kp = 1.6 atm)
- 10 litre
- 4 litre
- 2 litre
- 5 litre
Answer
(4) 5 litre
Solution
For SrCO3(s) SrO(s) + CO2(g): Kp = pCO2
⇒ Maximum pressure of CO2 = 1.6 atm (beyond this, CO2 combines with SrO).
Up to this point the amount of CO2 is constant at 400 K ⇒ Boyle's law:
p1V1 = p2V2
⇒ 0.4 20 = 1.6 V2
⇒ V2 = 5 L
Answer: (4)