Question

A magnesium ribbon is burnt in oxygen to give a white compound $X$ accompanied by the emission of light. If the burning ribbon is now placed in an atmosphere of nitrogen, it continues to burn and forms a compound $Y$. Write the chemical formula of $X$ and $Y$:

• A. $x\to MgO;y\to MgN$
• B. $x\to 2MgO;y\to M{g}_2{N}_3$
• C. $x\to MgO;y\to M{g}_3{N}_2$
• D. None of these

Answer 1

Answer: (C)

$x\to MgO;y\to M{g}_3{N}_2$

Magnesium ribbon burns in oxygen($O_2$) to form magnesium oxide ($MgO$).

$2Mg+O_2\to 2MgO$

Therefore $X$ is $MgO$.

Burning magnesium ribbon reacts with nitrogen($N_2$) to form

magnesium nitride($M{g}_3{N}_2$).

$3Mg+N_2\to M{g}_3{N}_2$

Therefore, $Y$ is $M{g}_3{N}_2$

Hence the correct option is C.