In balancing chemical equations, all you need to do is make it so that you have the same number of each element on both sides of the eqtn (if I have 5C on the left, I have to have 5C on the right — an element can’t magically appear or disappear); that being said:
(2)C2H6 + 7O2 ➡️ 6H2O + 4CO2
(12)HClO4 + P4O10 ➡️ 4H3PO4 + (6)Cl2O7
2N2 + (5)O2 + 2H2O ➡️ 4HNO3
(3)CaCl2 + 2Na3PO4 ➡️ (1)Ca3(PO4)2 + 6NaCl
4FeS + 7O2 ➡️ 2Fe2O3 + 4SO2
