A mixture of gases O2,H2 and CO are taken in a closed vessel containing charcoal. The graph that represents the correct behaviour of pressure with time is:
(A)(see structure)
(B)(see structure)
(C)(see structure)
(D)(see structure)✓ Correct
Answer: (D)
Solution
Charcoal is a strong adsorbent, and when the mixture of O2, H2 and CO stands over it the gas molecules are progressively taken up on its surface. As adsorption proceeds the number of molecules left in the gas phase falls, so the pressure drops steadily from its initial value and then levels off as the surface approaches saturation and equilibrium is reached. The correct behaviour is the curve in which the pressure decreases with time and flattens to a constant value.
JEE Main · 2020 · 09 Jan 2020 · Shift 2 · Single correct option