Осуществить превращения:
CH3Cl -> CH4 -> C2H6 -> X -> CH3 -> COOH

CH4->CH3Cl->C2H6->C2H5OH->CH3COOH

1) CH4+Cl2=CH3Cl+HCl

2) 2CH3Cl+2Na=CH3-CH3+2NaCl

3) CH3-CH3+Cl2=CH3-CH2Cl+HCl

4) CH3-CH2Cl+NaOH=CH3-CH2OH+NaCl

5) CH3-CH2OH+{O}=CH3COOH

X-C2H5OH