A)CH4+Cl2---свет---->CH3Cl+HCl;
2CH3Cl+2Na--t----->CH3-CH3+2NaCl;
CH3-CH3+Cl2--свет---->CH3-CH2-Cl+HCl;
CH3-CH2-Cl+2Na+CH3Cl---t----->CH3-CH2-CH3+2NaCl;
б)C+2H2---t,kat---->CH4;
CH4+Cl2---свет---->CH3Cl+HCl;
CH3Cl+2Na+CH3-CH2-Cl----t---->CH3-CH2-CH3+2NaCl;
CH3-CH2-CH3+Br2--свет---->CH3-CH2-CH2-Br+HBr;