Question

A student balanced the chemical equation for the reaction of magnesium with oxygen by writing Mg + O2 ? MgO2. What is wrong with this equation?

Answer 1

The equation was not balanced correctly because it was balanced by changing a subscript instead of changing coefficients. The correctly balanced equation is 2Mg + O2= 2MgO.

Is this correct for you?

Answer 2

There must be an additional Mg atom.

Step-by-step explanation:

The valence of Mg is +2 which means it can give two electrons to any other element thereby forming chemical bond. For this, there is requirement of an element which has valence of -2 or an element which has a deficiency of 2 electron to reach stable state. Oxygen has a valency of -2 which means it can take two electrons from a donor element such as Mg.

In a balanced equation the number of electrons/atom/molecule/ion/radicals

on the right and left side of equation must be equal.

So the balanced equation between Mg and O will be -

`Mg + O -----> MgO\\Or\\2 Mg + O_(2) ------> 2 MgO`