Question

(Repost) How would you balance the following chemical equation:

A) Place a 2 in front of Ca2
B) Place a 2 in front of O2
C) Place a 2 in front of CaO
D) It is already balanced

Answer 1

C, the reactants have an equal charge so there isn’t a need to have multiple of them. Because there’s two of each, there will we 2 of the product

Answer 2

C) Place a 2 in front of CaO

Step-by-step explanation:

The equation:

Ca2 +O2 → CaO is not balanced as there are 2 atoms of Ca from Ca2 on the left side and there is 1 atom of Ca from CaO on the right side, so add a 2 in front of CaO.

Ca2+O2 → 2CaO

On the left we have:

2 atoms of Ca

2 atoms of O

On the right we have:

2 atoms of Ca

2 atoms of O

The equation is now balanced as there are equal numbers of atoms of each side