12.) This does not follow the rule of conservation because on the reactant side there is one Na and two Cl while the product side only has one Na and Cl. They are not equal and do not have the same number of atoms for the different elements. In the law of conservation matter cannot be created or destroyed and this does not follow the law.
13.) 2Na + Cl2 —> 2NaCl
Put a 2 in front of Na and a 2 in front of NaCl
The answers is A= C/-13
C= 13A
