Question

Balance this equation. If a coefficient of "1" is required, choose "blank" for that box.

C2H4 + O2 → CO2 + H2O

Answer 1

C2H4 + O2 → CO2 + H2O

We want the same number of each element on each side.
Since there is only one compound on each side, we can start with carbon: When we double C02, we end up with 2 carbon atoms on each side.
When we double H20, we end up with 4 hydrogen atoms on each side.
The right side now contains 4 + 2 = 6 oxygen atoms, so we put a 3 in front of 02.
The result is:
C2H4 + 3O2 → 2CO2 + 2H2O

Answer 2

when balancing the equation you need to know how many moles reacted and how many were formed.To balance this equation we require 1 moles of C2H4, 3moles of O2 to form 2 moles CO2 and 2 moles H2o
therefore the equation is represented as
C2H4+3O2 ->2CO2+2H2O