Copy and complete the following paragraph using the options given in brackets:

Alkenes are a homologous series of (i) …………… [saturated/unsaturated] hydrocarbons characterized by the general formula (ii) …………… [C_nH_2n+2/C_nH_2n]. Alkenes undergo (iii) …………… [addition/substitution] reactions and also undergo (iv) …………… [hydrogentaion/dehydrogenation] to form alkanes.

Give one word or a phrase for the following statement:

The reaction in which carboxylic acid reacts with alcohol in the presence of conc. H₂SO₄, to form a substance having a fruity smell.

State one relevant reason for the following: Sodalime is preferred to sodium hydroxide in the laboratory preparation of methane.

Write the IUPAC name for the following compounds:

     A: acetaldehyde
     B: acetylene