Question

1 mole of a gas 'AB' dissociates to an extent of 10% at ${127}^{0}C$ according to AB $\rightleftharpoons$ A+B. Occupies a volume of $4\times {10}^4$ml. Find total pressure at this temp, assuming ideal gas behavior.

• A. 0.32 atm
• B. 1.46 atm
• C. 2.05 atm
• D. 0.902 atm

Answer 1

The correct option is D 0.902 atm

$AB\rightleftharpoons A+B$

Initial 1 mole 0 0

Eq. 0.9 0.1 0.1

from eq numbers of moles

total numbers of moles after

dissolution $0.9+0.1+0.1=1.1$

Now $PV=nRT$ (ideal behaviour)

$P=\frac{nRT}{V}$ $T=127+273=400K$

$R=Gasconstant=8.314J/K,mole$

take R=gas constant $=82.057=c{m}^{2}athert{s}^{-1}mol{e}^{-1}$ $=1c{m}^3=1ml$

$P=\frac{\left(1.1\right)\left(\mathrm{82.0.57}\right)mlatm{K}^{-1}m{l}^{-1}\times 400K}{4\times {10}^{4}mol}$

$P=0.902atm$