21.

IUPAC name of (CH₃)₃ CCl is

• n-butyl chloride

• 3-chloro butane

• 2-chloro-2-methylpropane

• t-butyl chloride

Hyperconjugation is most useful for stabilising which of the following carbocations?

• Neo-pentyl

• Tert-butyl

• Iso-propyl

• Ethyl

The isomerism that arises due to restricted bond rotation is

• metamerism

• optical isomerism

• position isomerism

• geometrical isomerism

Which of the following undergoes reduction with hydrogen peroxide in alkaline medium?

• Mn²⁺

• I₂

• PbS

• Fe²⁺

The maximum oxidation state exhibited by actinide ions is

• +5

• +4

• +7

• +8

Leaching is a process of

• reduction

• concentration

• refining

• oxidation

Electrolysis of fused NaCl will give

• Na

• NaOH

• NaClO

• NaClO₃

2 g of a radioactive sample having half-life of 15 days was synthesised on 1st Jan 2009. The amount of the sample left behind on 1st March, 2009 (including both the days) is

• 0 g

• 0.125 g

• 1 g

• 0.5 g

The rate equation for a reaction,

A $\to$ B

is r = k[ A]⁰. If the initial concentration of the reactant is a mol dm^-3 the half-life period of the reaction is

• $\frac{\mathrm{a}}{2\mathrm{k}}$

• $\frac{\mathrm{k}}{\mathrm{a}}$

• $\frac{\mathrm{a}}{\mathrm{k}}$

• $\frac{2\mathrm{a}}{\mathrm{k}}$

The one which has least iodine value is

• sunflower oil

• ginger oil

• ghee

• groundnut oil