Previous Year Papers

Download Solved Question Papers Free for Offline Practice and view Solutions Online.

Test Series

Take Zigya Full and Sectional Test Series. Time it out for real assessment and get your results instantly.

Test Yourself

Practice and master your preparation for a specific topic or chapter. Check you scores at the end of the test.

Equilibrium

Short Answer Type

51. Can equilibrium be achieved between water and its vapour in an open vessel? Explain your answer and say what happens eventually.

667 Views

Long Answer Type

52. A vessel has two compartments connected at the top. In one compartment (B), radioactive methyl iodide (CH₃I) is placed and in the other (A) normal methyl iodide (CH₃I) is placed. Will the vaporus over (A) and (B) become radioactive?
Will the radioactivity spread to the liquid in the compartment A? Discuss in terms of dynamic nature of the equilibrium between vapours and its liquid.

100 Views

53. A liquid is in equilibrium with its vapours in a sealed container at a fixed temperature. The volume of the container is suddenly increased.

(i) What is the initial effect of the change on the vapour pressure?

(ii) How do the rates of evaporation and condensation change pressure?

(iii) What happens when equilibrium is restored finally and what will be the Final vapour pressure?

250 Views

54. What are reversible and irreversible reactions? Give examples.

254 Views

55. Write a short note on the concept of chemical equilibrium.

Consider a general reversible reaction

(reaction carried out in a closed vessel).
In the beginning (i.e. at time t = zero), the concentrations of A and B are maximum and concentrations of C and D are equal to zero (as C and D are not formed). Hence at t = 0, the rate of forward reaction is maximum whereas the rate of backward reaction is minimum (almost equal to zero).

As the time passes, A and B are consumed whereas more and more of C and D are formed. Hence, the concentration of A and B decreases while that of C and D increases. Since the reaction is carried out in a closed vessel, therefore, the products C and D also react back among themselves to give back the reactants. This means that the chemical reaction proceeds both ways and is called reversible reaction. Therefore, the rate of forward reaction falls off with time while the rate of the backward reaction gradually increases.

Ultimately, a stage comes when the rate of the forward reaction becomes equal to the rate of backward reaction. The reaction is then said to be in a state of chemical equilibrium Thus, at equilibrium state, Rate of the forward reaction (R_f) = Rate of the backward reaction (R_b). The attainment of chemical equilibrium can be seen both in physical and chemical processes.

126 Views