51.

Thymine is

• 5-methyluracil

• 4-methyluracil

• 3-methyluracil

• 1-methyluracil

'Tocopherol' is the chemical name of

• vitamin K

• vitamin E

• vitamin H

• vitamin D

The following conversion is known as

CH₃-CH=O + H-CH₂CHO $\stackrel{\mathrm{Dilute} \mathrm{NaOH}}{\to }$ CH₃-CHOH-CH₂CHO

• Cannizzaro reaction

• aldol condensation

• polymerisation

• benzoin condensation

The yellow colour in NaCl crystals is due to

• excitation of electrons in F-centres

• reflection of light from Cl ions on the surface

• refraction of light from Na⁺ ions

• all of the above

Assertion : Change in colour of acidic solution of potassium dichromate by breath is used to test drunken drivers.

Reason : Change in colour is due to complexation of alcohol with potassium dichromate.

• 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: Phenol undergoes Kolbe's reaction whereas ethanol does not.

Reason : Phenoxide ion is more basic than ethoxide ion.

• 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 : Orlon is used as a synthetic fibre.

Reason : The monomer of orion is vinyl chloride

• 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 : Teflon is chemically inert substance.

Reason : Chloroform when treated with antimony trifluoride gives teflon.

• 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: Formic acid reduces mercuric chloride to mercurous chloride on heating, while acetic acid does not.

Reason: Formic acid is a stronger acid than acetic acid.

• 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 : Solubility of proteins is minimum at the isoelectric point.

Reason : At isoelectric point, protein molecule behaves as a zwitter ion.

• 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.