Give the formula and names of A, B, C and D in the following equations:

(a)

$\text{CH}$4 \xrightarrow[\text{-HCl}]{\text{Cl}2} \text{A} \xrightarrow[\text{-HCl}]{\text{Cl}2} \text{B}\xrightarrow[\text{-HCl}]{\text{Cl}2} \text{C}\xrightarrow[\text{-HCl}]{\text{Cl}_2} \text{D}

(b)
$\text{C}$2\text{H}2 \xrightarrow{\text{H}2} \text{A} \xrightarrow{\text{H}2} \text{B}\xrightarrow[\text{-HBr}]{\text{Br}2} \text{C}\xrightarrow[\text{-HBr}]{\text{Br}2} \text{D}

(c)
$\text{C}$2\text{H}4 + \text{B} \xrightarrow[\text{Nickle}]{200\degree\text{C}} \text{C}2\text{H}6

(a) A — CH₃Cl (Chloro methane)

B — CH₂Cl₂ (Di-chloromethane)

C — CHCl₃ (Tri-chloro methane)

D — CCl₄ (Carbon tetrachloride)

$\text{CH}$4 \xrightarrow[\text{-HCl}]{\text{Cl}2} \text{CH}3\text{Cl} \xrightarrow[\text{-HCl}]{\text{Cl}2} \text{CH}2\text{Cl}2\xrightarrow[\text{-HCl}]{\text{Cl}2} \text{CH}\text{Cl}3\xrightarrow[\text{-HCl}]{\text{Cl}2} \text{CCl}4

(b) A — C₂H₄ (ethene)

B — C₂H₆ (ethane)

C — C₂H₅Br (bromo-ethane)

D — C₂H₄Br₂ (1,2-Di-bromoethane)

$\text{C}$2\text{H}2 \xrightarrow{\text{H}2} \text{C}2\text{H}4 \xrightarrow{\text{H}2} \text{C}2\text{H}6 \xrightarrow[\text{-HBr}]{\text{Br}2} \text{C}2\text{H}5\text{Br}\xrightarrow[\text{-HBr}]{\text{Br}2} \text{C}2\text{H}4\text{Br}_2

(c) B — H₂ (Hydrogen)

$\text{C}$2\text{H}4 + \text{H}2 \xrightarrow[\text{Nickle}]{200\degree\text{C}} \text{C}2\text{H}_6