Question

please give me correct answer it is urgent​

Answer 1

Answer:

a) is Wurtz reaction in  substitute "cl" with "i" in the reactant  

b) is Swarts reaction substitute "br" with "f"  in the reactant  

Explanation:

a),b)

The reason for the above reaction is we cannot prepare the fluorine and iodine halocompounds directly beacuse of its electronegativity and reactivity respectively for f and i so we carry out the reaction of fluorine and iodine with already prepared haloalkanes to get the fluorine and iodine derivatives.

10.18

And answer for your q 10.18 p dicholorobenzene  has a greater melting point because of its symmetrical nature and  for stable lattice so that lattice enthalpy is higher  and even its melting point is higher do refer solid state for better clarification