Question

20. K for A(g) + B(g) = 3C(g) is 30 at 298 K. If a two
litre vessel contains 1, 2 and 5 moles of A, B and C
respectively, the reaction at 298 K shall
(1) Proceed from left to right
(2) Proceed from right to left
(3) Be at equilibrium
(4) Can't be predicted​

Answer 1

Answer:

proceed from right to left

as k=30 after solving according to data then Ans will be 31.25

so for k it proceed to left

Answer 2

Answer: (2) Proceed from right to left

Explanation:  

Equilibrium constant is defined as the ratio of concentration of products to the concentration of reactants each raised to the power their stoichiometric ratios. It is expressed as $K_{eq}$

K is the constant of a certain reaction when it is in equilibrium, while Q is the quotient of activities of products and reactants at any stage other than equilibrium of a reaction.

For the given chemical reaction:

$A(g)+B(g)\rightarrow 3C(g)$

The expression for $Q$ is written as:

$Q=\frac{[C]^3}{[A]^1[B]^1}$

$[A]=\frac{moles}{\text {Volume in L}}=\frac{1mol}{2L}=0.5M$

$[B]=\frac{moles}{\text {Volume in L}}=\frac{2mol}{2L}=1M$

$[C]=\frac{moles}{\text {Volume in L}}=\frac{5mol}{2L}=2.5M$

$Q=\frac{[2.5]^3}{[0.5]^1[1]^1}$

$Q=31.25$

Given : $K_{eq}$ = 30

Thus as $K_{eq}<Q$, the reaction will shift towards the left i.e. towards the reactant side.