21.

Action of acetylene on dilute H₂SO₄ gives :

• acetic acid

• acetaldehyde

• acetone

• acetoacetic ester

Oxidation state of Fe in Fe₃O₄ is :

• 3/2

• 5/4

• 4/5

• 8/3

Which of the following reaction produces hydrogen ?

• Mg + H₂O

• H₂S₂O₈ + H₂O

• BaO₂ + HCl

• Na₂O₂ + 2HCl

Which of the following is a chiral compound ?

• Hexane

• n-butane

• Methane

• 2,3,4-Trimethyl hexane

The length of C - C bond in benzene is :

• 1.22 A^o

• 1.54 A^o

• 1.39 A^o

• 1.56 A^o

Which of the following is most stable ?

• 1-butene

• 1-pentene

• 2-butene

• 2-pentene

Assertion: Stannous chloride gives a grey precipitate with mercuric chloride, but stannic chloride does not do so.
Reason: Stannous chloride is a powerful oxidising an agent which oxidises mercuric chloride to metallic mercury.

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

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

• If the assertion is true but the reason is false.

• If both the assertion and reason are false.

Assertion: Diamond is a bad conductor.
Reason: Graphite is a good conductor.

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

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

• If the assertion is true but the reason is false.

• If both the assertion and reason are false.

Which of the following is not an ore of iron ?

• Limonite

• Caniterite

• Magnetite

• None of these

For the reaction :

H₂ + Cl₂ $\stackrel{\mathrm{Sunlight}}{\to }$ 2HCl , the order of reaction is :

• 0

• 2

• 1

• 3