21.

The IUPAC name of the given compound is (CH₃)₃CCH₂C(CH₃)₃

• 2, 3,4,4-tetramethylpentane

• 1, 2, 2, 4-tetramethylpentene

• 2,2,4, 4-tetramethylpentane

• 3, 3-dimethylpentane.

What is 'A.' in the following reaction?

Assertion: Chloroform is stored in dark coloured bottles.

Reason: Chronic chloroform exposure may cause damage to liver and kidneys.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

Assertion : Saturated hydrocarbons are chemically less reactive.

Reason: All isomeric paraftins have same parent name.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

Assertion: Permanent hardness of water is removed by treatment with washing soda.

Reason: Washing soda reacts with soluble calcium and magnesium chlorides and sulphates in hard water to form insoluble carbonates.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

Assertion: Ortho and para-nitrophenol can be separated by steam distillation.

Reason: Para-nitrophenol is steam volatile due to intramolecular hydrogen bonding.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false.

A forms hcp lattice and B are occupying 1/3^rd of tetrahedral voids, then the formula of compound is

• AB

• A₃B₂

• A₂B₃

• AB₄

Rhombic sulphur dissolves best in

• CS₂

• H₂O

• ethanol 

• ether

Least coordination number is shown by

• Co₂(CO)₈

• Mn₂(CO)₁₀

• [Fe(en)₂NH₃]

• [Cr(OH)₃(NH₃)₃]

Enrichment of U²³⁵ is done by

• IF₇

• CIF₃

• IF₃

• ClF₅