Question

Write a balanced chemical equation for the following reaction: mercury oxide decomposes (breaks down) to produce mercury and oxygen.
A. 2HgO → 2Hg +O2
B. HgO → Hg +O
C. HgO →2Hg +O2
D. 2HgO → 2Hg +2O2

Answer 1

C

Oxygen defaults to O2 on its own, as does Bromine, Iodine, Nitrogen, Chlorine, Hydrogen and Fluorine. The way I was taught to remember those was to use their acronyms to spell BrINClHOF, brinkel-hoff.

Just one of those things.

Answer 2

Incorrect. Look at which one has equal number of each element on both sides.

Answer 3

@wolfe8
That's probably why I shouldn't come on this site at 1 in the morning.