Answer:
1. 2Mg + O2 —> 2MgO
2. 2H2 + O2 —> 2H2O
3. CH4 + 2O2 —> CO2 + 2H2O
Step-by-step explanation:
1. Magnesium + Oxygen —> Magnesium Oxide
Mg + O2 —> MgO
There are 2 atoms of O on the left side and 1 atom on the right side. It can be balance by putting 2 in front of MgO as shown below:
Mg + O2 —> 2MgO
There are 2 atoms of Mg on the right side and 1 atom on the left side. It can be balance by putting 2 in front of Mg as shown below:
2Mg + O2 —> 2MgO
Now the equation is balanced.
2. Hydrogen + Oxygen —> Water
H2 + O2 —> H2O
There are 2 atoms of O on the left side and 1 atom on the right side. It can be balance by putting 2 in front of H2O as shown below:
H2 + O2 —> 2H2O
There are 2 atoms of H on the left side and a total of 4 atoms on the right side. It can be balance by putting 2 in front of H2 as shown below:
2H2 + O2 —> 2H2O
Now, the equation is balanced.
3. Methane + oxygen à Carbon dioxide + Water
CH4 + O2 —> CO2 + H2O
There are 4 atoms of H on the left side and 2 atoms on the right side. It can be balance by putting 2 in front of H2O as shown below:
CH4 + O2 —> CO2 + 2H2O
There are 2 atoms of O on the left side and a total of 4 atoms on the right side. It can be balance by putting 2 in front of O2 as shown below:
CH4 + 2O2 —> CO2 + 2H2O
Now, the equation is balanced.