Question

Which equation obeys the law of conservation of mass? A. 2Fe+3O2 --> 2Fe2O3

B.4Fe+O2--> 2Fe2O3
C.Fe+O2--> Fe2O2
D. 4Fe+3O2--> 2Fe2O3

Answer 1

A. 2Fe+3O2 --> 2Fe2O3

Step-by-step explanation:

This is the only answer with a balanced equation. There are 2 Fe and 6 O on the reactant side. (3 is being distributed to the 2 in the element O). On the product side, there are 2 Fe and 6 O. The reactant and product side have the same amound of Fe and O.

Reactants (aka right side):

Fe- 2

O- 6

Products (aka left side):

Fe- 2

O- 6