Question

Which of the following is a correctly balanced equation?
A. 2Cu + O2 --> 2CuO

B. Mg + O2 --> MgO2

C. 3kCl + HNO3 --> 3HCl + KNO3

D. CaCO3 --> CaO + CO3

Answer 1

I think it C. by what I am reading so if it wrong I am sorry.

Answer 2

A correctly balanced equation has each side of the equation must have the same number of atoms. Atoms aren't created or destroyed in chemical changes.Each side of the equation must have the same number of atoms of each element. Atoms aren't converted into different types of atoms in chemical change.Each side of the equation must have the same total charge. Electrons aren't created or destroyed in chemical changes.

Answer 3

A is not balanced correctly because only half of the oxygen molecule is needed, but there is no 1/2 in front of O2 in the first equation, so it is unbalanced.

Answer 4

B is not balanced correctly because Magnesium oxide is MgO and not MgO2
The correct way to balance that is 2 Mg + O2 >> 2 MgO

Answer 5

C is not balanced incorrectly, this is the correct one,KCl + HNO3 = HCl + KNO3 sorry very hard to explain why it is incorrect

Answer 6

D is already balanced because there are the same number of atoms on each side, one Ca, one C and three O's on either side. That is how we know it is correct.

Answer 7

B is the only correct one