Question

Colour of magnesium oxide is:
A. White
B. Blue
C. Grey
D. Pink

Answer 1

Hint: Magnesium oxide is also known as magnesia. It was historically named as magnesia alba. It is of the same colour as that of quick lime or burnt lime (CaO). It can also be formed by an exothermic reaction by burning magnesium in air.

Complete step by step answer:
Magnesium is a naturally occurring mineral. Magnesium oxide (MgO), also known as magnesia is a white hygroscopic solid mineral that occurs naturally as mineral periclase and is a source of magnesium.
Magnesium is important for many systems in the body especially the muscles and nerves. Magnesium oxide is also used as a supplement to maintain adequate magnesium in the body. It is also used as an antacid to treat indigestion or to relieve constipation.
Magnesium oxide is produced by the calcination of magnesium carbonate or magnesium hydroxide. The chemical reactions for the same processes are:
\[MgC{O_3} \to MgO + C{O_2}\]
\[Mg{(OH)_2} \to MgO + {H_2}O\]
Magnesium oxide is a white hygroscopic solid mineral. Magnesium gives up two electrons to oxygen atoms to form this powdery product.

Hence, the correct answer is (A) White.

Additional information:
Some uses of magnesium oxide are:
It is used as a refractory material, i.e. it is physically and chemically stable at high temperatures.
MgO is one of the components in Portland cement in dry process plants.
Magnesium oxide is used for relief of heartburn and dyspepsia.

Note: Remember that burning of magnesium in air is a highly exothermic reaction. The burning of magnesium in air produces intense heat which can cause burns and initiate combustion in flammable materials.