Question

Carbon cannot be used to produce magnesium by chemical reduction of MgO because:

• A. Carbon is not a powerful reducing agent
• B. Magnesium reacts with carbon to form carbides
• C. Magnesium is less electropositive than carbon
• D. Carbon does not react with magnesium

Answer 1

The correct option is B Magnesium reacts with carbon to form carbides

Carbon cannot be used to produce magnesium by chemical reduction of $MgO$ because magnesium reacts with carbon to form carbides.
The reaction is represented as -
$2Mg+3C\stackrel{{2000}^{\circ }C}{\to }M{g}_2{C}_3$
i.e., $Mg$ at high temperature $\left({2000}^{\circ }C\right)$ combined with carbon and magnesium carbide is formed.