Haloalkanes and Haloarenes — Chemistry STD 12 Science — Question

Why does an aqueous solution of NaCl on electrolysis give H₂ gas at the cathode and not sodium metal?

Note: In the following questions a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.

1. Assertion and reason both are correct statements and reason is correct explanation for assertion.
2. Assertion and reason both are correct statements but reason is not correct explanation for assertion.
3. Assertion is correct statement but reason is wrong statement.
4. Assertion and reason both are incorrect statements.
5. Assertion is wrong statement but reason is correct statement.

Assertion: When NaCl is added to water a depression in freezing point is observed.
Reason: The lowering of vapour pressure of a solution causes depression in the freezing point.

How do you explain the presence of five —OH groups in glucose molecule?

Explain the use of Bayer reagent.

Write a reaction showing the acidic nature of methyl amine.

Some enzymes are named after the reaction, where they are used. What name is given to the class of enzymes which catalyse the oxidation of one substrate with simultaneous reduction of another substrate?

How can the reduction potential of an electrode be increased?

o-Nitrophenol has lower boiling point than p-nitrophenol. Explain.

What is the maximum oxidation state shown by actinoids?