Answer:

Bromine is more electronegative than hydrogen, creating a polar bond. This results in a permanent dipole (H^δ+-Br^δ-). The partially positive hydrogen atom (H^δ+) is attracted to the electron-rich double bond, allowing it to accept an electron pair.

Mechanism:

Answer:

The organic intermediate is a carbocation (positively charged). The inorganic intermediate is a bromide ion (negatively charged with a lone pair). The lone pair on the bromide ion forms a coordinate bond with the positively charged carbon.

Induced Dipole:

As the non-polar Cl₂ molecule approaches the electron-rich C=C bond, the electrons in the double bond repel the electrons in the Cl-Cl bond. This induces a temporary dipole (Cl^δ+-Cl^δ-), allowing the Cl^δ+ to act as an electrophile.

Propene reacts faster.

The reaction with propene proceeds via a secondary carbocation intermediate, whereas ethene proceeds via a primary carbocation. Secondary carbocations are more stable due to the positive inductive effect of two alkyl groups pushing electron density towards the positive charge. A more stable intermediate lowers the activation energy, increasing the rate of reaction.

H⁺ Mechanism:

H₂SO₄ Mechanism:

• HSO₄⁻: Acts as a Base (it accepts a hydrogen ion/proton to regenerate the sulfuric acid catalyst).
• CH₃CH₂CH₂⁺: Acts as an Acid (it donates a hydrogen ion/proton).

Industrial Conditions:

• Temperature: 300°C
• Pressure: 60-70 atm
• Catalyst: Concentrated Phosphoric Acid (H₃PO₄)