Осуществите превращения ch4--->ch3cl--->ch3-ch3--->Ich3ch3
СH4 + Cl2 -> CH3-Cl + HCl CH3-Cl + 2Na + Cl-CH3 -> CH3-CH3 + 2NaCl CH3-CH3 + I2 -> CH3-CH2-I + HI