Chemistry

This is a Multiple Choice Type Questions as classified in NCERT Exemplar

Ans: Correct option is (i)

High temperature is not favourable for physical adsorption since it is an exothermic process, hence the correct option is (i).

This is a Multiple Choice Type Questions as classified in NCERT Exemplar

Ans:  Correct option is (i)

As adsorption is an exothermic process so? H cannot be greater than zero, hence the correct option is (i).

This is a Multiple Choice Type Questions as classified in NCERT Exemplar

Ans: Correct option is (i)

Extent of adsorption depends on the concentration of the solute in a solution. The concentration of adsorbate increases the interaction between adsorbate and adsorbent thus the extent of adsorption also increases; hence the correct option is (i).

This is a Multiple Choice Type Questions as classified in NCERT Exemplar

Ans: Correct option is (ii)

As the process of adsorption is an exothermic one; physical adsorption occurs readily at low temperature and decreases with an increase in the temperature as equilibrium shifts in the backward direction. This is known as Le-Chatelier's principle, hence the correct option is (ii).

This is a Multiple Choice Type Questions as classified in NCERT Exemplar

Ans: Correct option is (iii)

When both adsorption and absorption occur simultaneously it is known as sorption; hence the correct option is (iii).

This is a Multiple Choice Type Questions as classified in NCERT Exemplar

Ans: Correct option is (iv) 

As gas-gas forms up a homogeneous composition, so the correct option is (iv).

This is a Multiple Choice Type Questions as classified in NCERT Exemplar

Ans: Correct option is (iv)

In equilibrium ΔG=0 so ΔG=ΔH-TΔS which means ΔH=TΔS therefore the correct option is (ii).

This is a Multiple Choice Type Questions as classified in NCERT Exemplar

Ans: Correct option is (iii)

In homogeneous catalysis, the reactant as well as the product both are in same phase and composition is uniform throughout hence the correct option is (iii).

This is a Short Answers Type Questions as classified in NCERT Exemplar

Ans: The rate of an enzyme reaction is maximum at a definite temperature, called the optimum temperature. On either side of the optimum temperature, the enzyme activity decreases. The optimum temperature range for enzymatic activity is 298-310 K. Human body temperature being 310 K is suited for enzyme-catalysed reactions. Therefore, during fever, catalytic activity of the enzyme may get affected.

This is a Short Answers Type Questions as classified in NCERT Exemplar

Ans: When gaseous molecules come in contact with the surface of a solid catalyst, a weak chemical combination takes place between the surface of the catalyst and the gaseous molecules, which increases the concentration of reactants on the surface. Different molecules adsorbed side by side have better chance to react and form new molecules. This enhances the rate of reaction. Also, adsorption is an exothermic process. The heat released in the process of adsorption is utilised in enhancing the reaction rate.