(a) The condition of the reaction is the presence of ultra-violet light or sunlight.
(ii) Substitution reaction.
(iii) Uses of methane are: (1) It is used as a fuel (2) It is used for making hydrogen, carbon black, carbon (iv) oxide; etc.
(iv) Methane occur as natural gas or refinery gas

(b)(i) (i) Hydrogen is evolved. (ii) Resulting liquid is both colourless (iii) Both reactions are exothermic
(ii)


(iii) Heavy-chemicals are chemicals that pre made in large quantities while fine chemicals are produced in small quantities.
(iv) Examples of heavy chemicals are: H\(_2\)SO\(_4\), NaOH, fertilizer, alum. Examples of fine chemicals are dyes, photographic chemicals, analytical chemicals, drugs.

(c)(i) Empirical formula of X and Y; No of atoms of C = \(\frac{92.3}{12}\) = 7.69
No. of atoms of H = \(\frac{7.7}{1}\)
= 7.7
Ratio of atoms atoms of C:H = \(\frac{7.69}{7.69}\) : \(\frac{7.7}{7.69}\) ; 1 : 1
Empirical formula = CH
(ii) Let the molecular formula of X be (CH)n ; (12 + 1)n = 13n ;
13n = 26
n = \(\frac{26}{13}\) = 2 molecular formula of X =C \(_2\)H \(_2\);
Let the molecular formula of Y be (CH)Y
(12 + 1) Y = 13Y ; 13Y = 78 ; Y = \(\frac{78}{13}\) = 6 ;
Molecular formula of Y = C \(_6\)H \(_6\).
(d)(i) Hydrolysis (ii) Amino acids (iii) Functional groups or amino acids are: amino group (--NH \(_2\)) ai carboxylic group (--COOH).