MgO --->
Mg + O
or is it Mg + O2 (subscript)
since o is usually diatomic
2MgO ==> 2Mg + O2
For Zn (CO3) =>> Zn + CO3 or would it be ZnO + CO2 how would you determine this?
Carbonates, when heated, usually decompose to CO2 and the metal oxide so
ZnCO3 ==> ZnO + CO2. Also you know there is a CO and a CO2 but no CO3 (although the [CO3]^2-) exists--as in ZnCO3, Na2CO3, etc).
The correct balanced equation for the decomposition of MgO can be determined by considering the oxidation states of the elements involved.
MgO is composed of magnesium (Mg) and oxygen (O). Magnesium typically has an oxidation state of +2, while oxygen has an oxidation state of -2.
When MgO decomposes, it breaks down into its constituent elements. Since magnesium has an oxidation state of +2, it will form Mg2+ ions when oxidized. On the other hand, oxygen normally exists as O2, with an oxidation state of -2.
Therefore, the balanced equation for the decomposition of MgO is:
2MgO ⟶ 2Mg + O2
In this equation, two MgO molecules yield two magnesium ions (Mg) and one diatomic oxygen molecule (O2).
Remember that in chemical equations, the numbers in front of the formulas or elements represent the stoichiometric coefficients, which indicate the ratio of reactants and products.