Name the following organic compounds:

(i) The compound with three carbon atoms whose functional group is a carboxyl.

(ii) The first homologue whose general formula is C_nH_2n

(iii) The compound that reacts with acetic acid to form ethyl ethanoate

(iv) The compound formed by complete chlorination of ethyne.

Give balanced chemical equations for the preparation of :

(i) Ethene from bromoethane

(ii) Ethyne using calcium carbide

(iii) Methane from sodium acetate.

Name the gas evolved: Ethene undergoes hydrogenation reaction.

Choose the correct answer from the options: The organic compound having a triple carbon-carbon covalent bond, is

A: C₃H₄
B: C₃H₆
C: C₃H₈
D: C₄H₁₀