Pentavalence in phosphorous is more stable when compared to that of nitrogen even through they belong to same group is due to

• reactivity of phosphorous

• inert nature of nitrogen

• dissimilar electronic configuration

• larger size of phosphorous atom

A chemical reaction was carried out at 300 K and 280 K. The rate constants were found to be K₁ and K₂ respectively. Then

• K₂ ≈ 0.25 K₁

• K₂ ≈ 0.5 K₁

• K₂ ≈ 4 K₁

• K₂ ≈ 2 K₁

A smuggler could not carry gold by depositing iron on gold surface since

• gold has higher standard reduction potential than iron

• gold has lower standard reduction potential than iron

• gold is denser

• iron rusts

Kinetic theory of gases presumes that collision between the molecules to be perfectly elastic because

• collisions will not split the molecule

• the molecules are tiny

• the molecules are rigid

• the temperature remains constant irrespective of collisions

In the case of a radio isotope the value of T_1/2 and λ are identical in magnitude. The value is

• 0.693

• (0.693)^1/2

• 1/ 0.693

• (0.693)²

Heat treatment alters the properties of steel due to

• chemical reaction on heating

• partial rusting

• change in the residual energy

• change in the lattice structure due to differential rate of cooling

Glacial acetic acid is obtained by

• chemically separating acetic acid

• treating vinegar with dehydrating agents

• crystallising, separating and melting acetic acid

• distilling vinegar

An organic acid without a carboxylic acid group is

• picric acid

• oxalic acid

• vinegar

• ascorbic acid

49.

An ester used as medicine is

• ethyl benzoate

• methyl salicylate

• methyl acetate

• ethyl acetate

Reaction of aniline with benzaldehyde is

• polymerisation

• condensation

• addition

• substitution