Chemistry - Chemical Equilibrium Question with Solution | TestHub
In a vessel of 1.0 L capacity, O2(g) at 0.20 atm and HCl(g) at 0.80 atm are allowed to react in presence of liquid water at 47°C.
4HCl(g) + O2(g) ⇌ 2Cl2(g) + 2H2O(g); KP = 6.25 × 109 atm-1.
The volume of liquid water is negligible but it is enough to keep equilibrium with water vapour. The vapour pressure of water at 47°C is 0.10 atm. Select the correct statement(s) regarding the equilibrium mixture.
Options:(select one or more)
Answer:
Solution:
Liquid water keeps the water vapour pressure at 0.10 atm, so (a) is wrong HCl and O2 are present in the ratio 0.80 : 0.20 = 4 : 1 and KP is very large, so the reaction is almost complete
Cl2 formed is 2(0.20) = 0.40 atm, so (b) is correct
Let PO2 = y, then PHCl = 4y
KP = (0.40)2(0.10)2/[(4y)4 y] = 0.0016/(256 y5) = 6.25 × 109
y5 = 1.0 × 10-15, so y = 1.0 × 10-3 atm, so (c) is correct
PHCl = 4y = 4.0 × 10-3 atm, so (d) is correct
The correct statements are (b), (c) and (d).
