Question

1.2 moles of So3 are allowed to dissociate in
a 2 litre vessel the reaction is 2so3(g)
2so2(g) +O2(g) and the concentration of oxygen
at equilibrium is 0.1 mole per litre. The total
number of moles at equilibrium will be
2) 1.4 3) 0.8 4) 1.6
1) 2

Answer 1

answer : option (2) 1.4

explanation : number of moles of SO3 = 1.2 mol

concentration of O2 = 0.1 M

volume of vessel = 2 litres

so, no of moles of O2 = 0.1 × 2 = 0.2 mol

chemical reaction is....

2SO3(g) ⇔2SO2(g) + O2(g)

at t = 0 1.2 0 0

at eq 1.2 - 2 × 0.1 2 × 0.2 0.2

0.8 0.4 0.2

total number of moles at equillibrium = no of moles of SO3 + no of moles of SO2 + no of moles of O2

= 0.8 + 0.4 + 0.2 = 1.4

hence, option (2) is correct.