# Ethylene reacts to give C_2H_4O_2...what is the product?

Now, clearly, the ${C}_{2} {H}_{4}$ reactant is $\text{ethylene}$, ${H}_{2} C = C {H}_{2}$.
But the ${C}_{2} {H}_{4} {O}_{2}$ product could be $\text{acetic acid}$, ${H}_{3} C - C {O}_{2} H$; it could be $\text{1,2-dioxetane}$, a cyclic peroxide; it could be a cyclic ether. Unless you specify the product, we cannot suggest its synthesis.