Question:

1 mole of $H_{2}$ and 2 moles of $I_{2}$ are taken initially in a 2 litre vessel. The number of moles of $H_{2}$ at equilibrium is 0.2. Then the number of moles of $I_{2}$ and $HI$ at equilibrium are

Updated On: Jul 28, 2022
  • $1.2, 1.6$
  • $1.8, 1.0$
  • $0.4, 2.4$
  • $0.8, 2.0$
Hide Solution
collegedunia
Verified By Collegedunia

The Correct Option is A

Solution and Explanation

At equilibrium number of moles of $H_{2} = 0.2$ means $0.8$ moles of $H_{2 }$ reacts with $(2 - 0-8)$ moles of $I_{2}$ to form $(2\times 0.8)$ moles of $HI$ $\begin{matrix}&H_{2}&+&I_{2}& {<=>}&2HI&&\\ \text{Initial no. of moles}&1&&2&&0\\ \text{No. of moles at equilibrium }&0.2&&(2-0.8)=1.2&&2\times 0.8=1.6\end{matrix}$
Was this answer helpful?
0
0

Top Questions on Law Of Chemical Equilibrium And Equilibrium Constant

View More Questions

Concepts Used:

Law of Chemical Equilibrium

Law of Chemical Equilibrium states that at a constant temperature, the rate of a chemical reaction is directly proportional to the product of the molar concentrations of the reactants each raised to a power equal to the corresponding stoichiometric coefficients as represented by the balanced chemical equation.

Let us consider a general reversible reaction;

A+B ↔ C+D

After some time, there is a reduction in reactants A and B and an accumulation of the products C and D. As a result, the rate of the forward reaction decreases and that of backward reaction increases. 

Eventually, the two reactions occur at the same rate and a state of equilibrium is attained. 

By applying the Law of Mass Action;

The rate of forward reaction;

Rf = Kf [A]a [B]b

The rate of backward reaction;

Rb = Kb [C]c [D]d

Where,

[A], [B], [C] and [D] are the concentrations of A, B, C and D at equilibrium respectively.

a, b, c, and d are the stoichiometric coefficients of A, B, C and D respectively.

Kf and Kb­ are the rate constants of forward and backward reactions.

However, at equilibrium,

Rate of forward reaction = Rate of backward reaction.

Kc is called the equilibrium constant expressed in terms of molar concentrations.

The above equation is known as the equation of Law of Chemical Equilibrium.