For carbanion

Stability order will be

• P > Q > S > R

• P > R > Q > S

• Q > R > S > R

• S > R > Q > P

Which one of the following acts as a nucleophile?

• (CH₃)₃N

• BF₃

• $\stackrel{+}{\mathrm{N}}$O₂

• ${\mathrm{CH}}_3 - \stackrel{+}{\mathrm{C}} = \mathrm{O}$

Which of the following compounds have highest melting point?

• Only I

• Only II

• I and II

• II and III

Identify the major product 'X' obtained in the following reaction.

2, 3-dimethyl butan-2-ol $\stackrel{\mathrm{conc}. {\mathrm{H}}_2{\mathrm{SO}}_4}{\to }$ X

Addition ofwater to alkynes occurs in acidic medium and in the presence of Hg²⁺ ions as a catalyst. Which of the following products will be formed on addition of water to but-1-yne under these conditions?

• CH₃CH₂CH₂CHO

• CH₃CH₂COCH₃

• CH₃CH₂COOH

• CH₃COOH + HCHO

696.

Which one of these is not true for benzene?

• It forms only one type of mono-substituted product

• There are three carbon-carbon single bonds and three carbon-carbon double bonds

• Heat of hydrogenation of benzene is less than its theoretical value

• The bond angle between carbon-carbon bonds is 120°

CH₃CHO +HCHO $\underset{\mathrm{Heat}}{\overset{\mathrm{Dil}. \mathrm{NaOH}}{\to }}$ A $\underset{{\mathrm{H}}_3{\mathrm{O}}^{+}}{\overset{\mathrm{HCN}}{\to }}$ B

The structure of compound B is

Which of the following statement is correct ?

• +I group stabilises a carbocation

• +I group stabilises a carbanion

• -I group stabilises a carbocation

• -I group stabilises a free radical

Which of the following can give a Grignard reagent when reacted with magnesium in dry ether?

• C₂H₆

• C₂H₅Cl

• C₂H₅OH

• C₂H₅CN

t-butyl chloride preferably undergo hydrolysis by

• S_N1 mechanism

• S_N2 mechanism

• Any of (a) and (b)

• None of these