Science (English Medium) Class 12 - CBSE Question Bank Solutions for Chemistry

Conductivity of an electrolytic solution depends on:

(i) nature of electrolyte.

(ii) concentration of electrolyte.

(iii) power of AC source.

(iv) distance between the electrodes.

Conductivity_K, is equal to:

(i) `1/R l/A`

(ii) `G^∗/R`

(iii) Λ_m

(iv) `l/A`

In an aqueous solution how does specific conductivity of electrolytes change with addition of water?

Assertion: Conductivity of all electrolytes decreases on dilution.

Reason: On dilution number of ions per unit volume decreases.

Assertion: For measuring resistance of an ionic solution an AC source is used.

Reason: Concentration of ionic solution will change if DC source is used.

For a certain reaction large fraction of molecules has energy more than the threshold energy, yet the rate of reaction is very slow. Why?

Match the items of Column I and Column II.

Match the items of Column I and Column II.

Describe how does the enthalpy of reaction remain unchanged when a catalyst is used in the reaction.

Which of the following process does not occur at the interface of phases?

Which of the following statements are correct about solid catalyst?

(i) Same reactants may give different product by using different catalysts.

(ii) Catalyst does not change ∆H of reaction.

(iii) Catalyst is required in large quantities to catalyse reactions.

(iv) Catalytic activity of a solid catalyst does not depend upon the strength of chemisorption.

Why is desorption important for a substance to act as good catalyst?

How does a solid catalyst enhance the rate of combination of gaseous molecules?

Do the vital functions of the body such as digestion get affected during fever? Explain your answer.

What do you understand by shape selective catalysis? Why are zeolites good shape selective catalysts?

In the extraction of copper from its sulphide ore, the metal is formed by the reduction of \[\ce{Cu2O}\] with ______.

In the metallurgy of aluminium ______.

Choose the correct option of temperature at which carbon reduces \[\ce{FeO}\] to iron and produces \[\ce{CO}\].

Below point ‘A’ \[\ce{FeO}\] can ______.

For the reduction of \[\ce{FeO}\] at the temperature corresponding to point D, which of the following statements is correct?