Answer :
The question is incomplete, the complete question is;
Balance the following equations by inserting the proper coefficients.
CH4 + O2 ---------------> CO2 +H2O
CaCl2 + AgNO3 ----->Ca(NO3)2 +AgCl
C2H6O + O2----------->CO2 +H2O
Answer:
CH4 + 2O2 ---------------> CO2 +2H2O
2AgNO3 + CaCl2 → Ca(NO3)2 + 2AgCl
C2H6O + 3O2 → 2CO2 + 3H2O
Explanation:
You see, when we set out to balance chemical reaction equations, ultimately, our aim is to ensure that the number of atoms of each element on the reactant side is exactly the same as the number of atoms of the same element on the products side.
We do this by counting the number of atoms required to have a balanced reaction equation and then adding coefficients in order to have a balanced chemical reaction equation.
This is what have been done in balancing the three reaction equations shown in the answer section.