Which of the following is a correctly balanced equation? a. naclo3 → nacl + 3o2 b. 2hgo → 2hg + o2 c. 2zns + o2 → 2zno + 2so2 d. 4co + fe3o4 → 4co2 + fe e. 2fe + 2cl2 → 2fecl3

The correct answer for this is B. Count up the atoms. They should be equal for each side of the equation.

B. 2HgO → 2Hg + O2

Explanation:

In order to have a correctly balanced equation, you need to have the same amount of elements and molecules of those given elements in both sides of the equation, so in this one there hare 2 molecules of Hg and 2 of Oxygen in the left, and in the rigth, there are 2 Hg, and one molecule of O2 which are 2 molecules of oxygen. So the one that is correctly balanced is B. 2HgO → 2Hg + O2