Electrophilic addition reactions proceed in two steps. The first step involves the addition of an electrophile. The major intermediate formed in the first step is -

${\mathrm{H}}_3\mathrm{C}-\mathrm{HC}={\mathrm{CH}}_2+{\mathrm{H}}^{+}\to$?

1. $2°$ carbanion

2. $1°$ carbocation

3. $2°$ carbocation

4. $1°$ carbanion

The addition of HCl to an alkene proceeds in two steps. The first step is the attack of H⁺ ion on the double bond portion. The same can be shown as-

1.		2.
3.		4.	All of these are possible

Electrophiles are electron-seeking species. Which of the following groups contain only electrophiles?

(a) \(\mathrm {BF_3, NH_3, H_2O} \)

(b) \(\mathrm {AlCl_3, SO_3 , NO_2^+} \)

(c) \(\mathrm {NO_2^+ , CH_3^+, CH_3-C^+\text=O} \)

(d) \(\mathrm {C_2H_5^-,H_3C -\dot{C}H_2,C_2H_5^+} \)

 
Choose the correct option:

1. (a, b)

2. (b, c)

3. (c, d)

4. (a, d)

A nucleophile is a species that should have

(a) A pair of electrons to donate

(b) Positive charge

(c) Negative charge

(d) Electron-deficient species

 
Choose the correct option

1. (a, b)

2. (b, c)

3. (c, d)

4. (a, c)