Ethylene is a natural stimulator of fruit ripening: its accumulation in fruits accelerates their ripening.

Ethylene is a natural stimulator of fruit ripening: its accumulation in fruits accelerates their ripening. The earlier the accumulation of ethylene begins, the earlier the fruits ripen. Therefore, ethylene is used to artificially accelerate the ripening of fruits. Derive the formula for ethylene if it is known that the mass fraction of carbon is 85.7%, and the mass fraction of hydrogen is 14.3%. The relative molecular weight of this substance is 28.

Given:
Ethylene – CxHy
ω (C in CxHy) = 85.7%
ω (H in CxHy) = 14.3%
Mr (CxHy) = 28

Find:
CxHy -?

Solution:
1) Calculate the index for the carbon atom in the ethylene molecule:
N (C in CxHy) = (ω (C in CxHy) * Mr (CxHy)) / (Ar (C) * 100%) = (85.7% * 28) / (12 * 100%) = 2;
2) Calculate the index for the hydrogen atom in the ethylene molecule:
N (H in CxHy) = (ω (H in CxHy) * Mr (CxHy)) / (Ar (H) * 100%) = (14.3% * 28) / (1 * 100%) = 4;
3) Unknown substance – ethylene – C2H4.

Answer: Unknown substance – ethylene – C2H4.