ALKANES

Preparation of alkanes can be divide into 4 which are hydrogenation of alkanes, reduction of alkyl halide, wurtz reaction and hydrolysis of grignard reagent. 

Hydrogenation of alkanes is addition of hydrogen (H) to an alkenes for forming an alkanes with platinum(Pt), palladium (Pd) and nickel (Ni) as a catalyst.

Reduction of alkyl halide is addition of Zink (Zn) to the alkyl halide to form an alkanes with HX as the catalyst. "X" represent halogen group such as (Cl, Br, I).

Wurtz reaction is addition of Sodium atom (Na) to the alkyl halide with ether as the catalyst to form an alkanes. 2Na been used in the example because i want to show the balance chemical equation.

Hydrolysis of grignard reagent involved two step which firstly form grignard reagent and the second is forming the alkanes. Forming grignard reagent is combination of alkyl with magnesium (Mg) and X which is halogen group. The second step is addition water (H2O) to the grignard reagent with hydrogen ions as catalyst to form an alkanes.

Reaction of an alkanes can be divided into three which halogenation, ring opening and combustion.

Halogenation have three step which initiation, propagation and termination. 
Initiation is breaking halogen to the free radical by addition of UV. 

Propagation have two step, the first one is alkane and free radical halogen will forming free radical alkane and halogen. Second, free radical alkane will react with halogen to form alkyl halide and free radical halogen. 

Termination have three step, first free radical halogen react with free radical halogen forming halogen. Second, free radical alkane react with free radical halogen forming alkyl halide. Third step, free radical alkane react with free radical carbon forming alkane.

Ring opening only occurs for cyclopropane. Cyclopropane can involved in substitution or addition process.

Combustion is process alkanes react with oxygen and forming carbon dioxide and water.

Baeyer strain theory explain about angle bond, angle strain and the reactivity. cyclopentane has the highest angle bond follow by cylobutane and cyclopropane. However, cyclopropane has the highest angle strain and be the most reactivity follow by cyclobutane and cyclopropane.