Question

In a common experiment in the general chemistry laboratory, magnesium metal is heated in air to produce MgO. MgO is a white solid, but in these experiments it often looks gray, due to small amounts of Mg3N2 , a compound formed as some of the magnesium reacts with nitrogen. Write a balanced equation for each reaction.

Answer 1

Explanation:

When magnesium metal burns is heated i the air it forms magnesium oxide.The balanced chemical reaction is given as:

$2Mg+O_2\rightarrow 2MgO$

2 moles of magnesium metal when reacts with 1 moles of oxygen it gives 2 moles of magnesium oxide which is white in color.

Some times along with formation of magnesium oxide small amount of magnesium nitride also produced due to which magnesium oxide appears grey in color .The balanced chemical reaction is given as:

$3Mg+N_2\rightarrow Mg_3N_2$

3 moles of magnesium combines with 1 mol of nitrogen gas to to give 1 mol of magnesium nitride.