
Total no. of moles at equilibrium = 80 + 20 + 20 = 120

2Al + Cr2O3 → 2Cr + Al2O3
ΔHr0 = [2ΔHf (Cr) + ΔHf (Al2O3)]–
[2ΔHf (Al) + ΔHf
(Cr2O3)] ΔHr0 = [0 + (–
1596 kJ)]– [0 + (– 1134)]
ΔHr0 = – 1596
kJ + 1134 kJ
ΔHr0 = – 462
kJ
Given, (KH)A = x
(KH)B = y
xA/xB = 0.2
(xA/xB)in solution = ?
PA = x (xA) in solution –
(1)
PB = y (xB) in solution –
(2)
(xA/xB)in solution = (PB/PA)
. (x/y) = (xB/xA) . (x/y) = (1/0.2) . (x/y) = 5x/y

isThe reduction reaction of the oxidising agent(MnO4–)
involves gain of 3 electrons.
Hence the equivalent mass = (Molar mass of KMnO4)/3
= 158.1/3 = 52.7
Orbital angular momentum = √(l(l+1) h/2π
For d orbital = √(2 x 3) h/2π = √6 h/2π