Different hydrogen atoms in the compound are represented by alphabets:
$CH_3(A)-CH=CH(B)-CH_2(C)-CH_2(D)-CH(E)(CH_3)_2(F)$
Arrange them in decreasing order of reactivity towards free radical substitution.

Write the reactions for the preparation of ethane from the following:
$(i)$ Acetic acid $(CH_3COOH)$
$(ii)$ Methane $(CH_4)$
$(iii)$ Acetate ion $(CH_3COO^{-})$

Given below are two statements:
Statement $I$: Methane can be prepared by decarboxylation of sodium ethanoate, Kolbe's electrolysis of sodium acetate and reaction of $CH_3MgBr$ with water.
Statement $II$: Methane cannot be prepared from unsaturated hydrocarbons and by Wurtz reaction.
In the light of the above statements, choose the correct answer from the options given below.

Identify the product $Z$ in the following series of reactions: $CH_3CH_2OH$ $\xrightarrow{SOCl_2, \Delta} X$ $\xrightarrow{Mg, \text{Dry ether}} Y$ $\xrightarrow{NH_3} Z + Mg(Cl)(NH_2)$

Complete the following reactions:
$(i)$ $n$-heptane $\xrightarrow[773 \ K, 10-20 \ atm]{Cr_2O_3/V_2O_5/Mo_2O_3}$ ?
(ii) $CH_4 + O_2 \xrightarrow[523 \ K, 100 \ atm]{Cu}$ ?

Ethane is subjected to a combustion process. During the combustion,the hybrid state of carbon changes from