The gas responsible for explosions in coal mines is .......

The most important method of preparation of hydrocarbons of lower carbon number is

Select the chain propagation steps in the free-radical chlorination of methane.
$(1) \, Cl_2 \to 2Cl^{\bullet}$
$(2) \, Cl^{\bullet} + CH_4 \to CH_3Cl + H^{\bullet}$
$(3) \, Cl^{\bullet} + CH_4 \to CH_3^{\bullet} + HCl$
$(4) \, H^{\bullet} + Cl_2 \to HCl + Cl^{\bullet}$
$(5) \, CH_3^{\bullet} + Cl_2 \to CH_3Cl + Cl^{\bullet}$

Weight $(g)$ of two moles of the organic compound,which is obtained by heating sodium ethanoate with sodium hydroxide in the presence of calcium oxide is:

Heating sodium acetate with sodalime gives......

$n$-butane on heating with a catalytic mixture of $AlCl_3$ and $HCl$ gives: