41.

Consider the folowing reaction,

A → Products

This reaction is completed in 100 mins. The rate constant of this reaction at t₁ = 10 min is 10^-2 min^-1. What is the rate constant (in min^-1) at t₂ = 20 min.

• 2 × 10^-2

• 10^-2

• 5 × 10^-3

• 0.1

Consider the following reactions,

C₂H₂ $\underset{500°\mathrm{C}}{\overset{\mathrm{red} \mathrm{hot} \mathrm{iron} \mathrm{tube}}{\to }}$ A

A $\underset{70°\mathrm{C}}{\overset{\mathrm{conc}. {\mathrm{HNO}}_3, \mathrm{conc}. {\mathrm{H}}_2{\mathrm{SO}}_4}{\to }}$ B

B $\stackrel{{\mathrm{LiAlH}}_4}{\to }$ C₆H₅-N=N-C₆N₅

A and B are

• A = C₂H₄; B = C₆H₆

• A = C₂H₆; B = C₆H₅NH₂

• A = C₂H₄; B = C₆H₅NH₂

• A = C₆H₆; B = C₆H₅NO₂

Which one of the following is used in the preparation of styrene? 

• CH₃CHO

• P₂O₅

• CH₄

• C₆H₆

Ethanol,when reacted with PCl₅ gave A, POCl₃ and HCl. A reacts with silver nitrite to form B (major product) and AgCl. A and B are respectively

• C₂H₅Cl and C₂H₅OC₂H₅

• C₂H₆ and C₂H₅OC₂H₅

• C₂H₅Cl and C₂H₅NO₂

• C₂H₆ and C₂H₅NO₂

Chloroethane reacts with X to form diethyl ether. What is X ?

• NaOH

• H₂SO₄

• C₂H₅ONa

• Na₂S₂O₃

3 moles of ethanol reacts with one mole of phosphorus tribromide to form 3 moles of bromo-ethane and one mole of X. Which of the following is X?

• H₃PO₄

• H₃PO₂

• HPO₃

• H₃PO₃

Absolute alcohol (100% alcohol) is prepared by distillmg rectified spirit over

• Na

• CaCl₂

• Mg

• Mg(OC₂H₅)

When acetaldehyde is reacted with LiAlH₄, what is the product formed?

• CH₃COOH

• CH₃CH₂OH

• CH₃OH

• HCOOH

Acetic acid is reacted with metallic sodium to form hydrogen and X. When X is heated with sodalime, Y and sodium carbonate are formed. Y is .

• C₂H₆

• CH₄

• CH₃COONa

• CH₃CONH₂

The metal ion present in vitamin B₁₂ is

• Co³⁺

• Co²⁺

• Fe²⁺

• Fe³⁺