preparation of alkane

Question 1

catalytic hydrogenation
sabatier-sendrens reaction

Answer 1

alkene to alkane
Ni/Pd/Pt
methane gas cannot be prepared

Question 2

reduction of alkyl halide

Answer 2

in the presence of Zn and dil.HCl
reactivity: I>Br>Cl
alkyl fluoride cannot be used

Question 3

ionic mechanism of Wurtz Reaction
(CH4 cannot be prepared)

Answer 3

breaking of R-X into R (free rad) and X(anion) and Na into Na+ and 1e that forms an alkene.

Question 4

Kolbe’s reaction
(methane cannot be prepared)

Answer 4

electrolysis of sodium or potassium salt of carboxylic acid (fatty acid)

Question 5

about KR

Answer 5

this method of preparation is applicable to the preparation of symmetrical alkanes only and not suitable for the preparation of methane. in kolbe’s electrolytic method, the alkane obtained is always a higher alkne due to the formation of C-C bond restricting the formation of methane by this process.