Question

Which of the following is true for calcination of a metal ore?

• A. It makes the ore more porous.
• B. The ore is heated to a temperature when fusion just begins.
• C. Hydrated salts lose their water of crystallisation.
• D. Both (a) and (c) above

Answer 1

The correct option is D Both (a) and (c) above

Calcination is the process of heating the ore in the absence of air.

Calcination of a metal ore makes it very porous and they lose their water of crystallisation.
$F{e}_2{O}_3.x{H}_{2}O\left(s\right)\stackrel{\Delta }{\to }F{e}_2{O}_3\left(s\right)+x{H}_{2}O\left(g\right)ZnC{O}_3\left(s\right)\stackrel{\Delta }{\to }ZnO\left(s\right)+C{O}_2\left(g\right)CaC{O}_3.MgC{O}_3\left(s\right)\stackrel{\Delta }{\to }CaO\left(s\right)+MgO\left(s\right)+2C{O}_2\left(g\right)$
Hence option (d) is correct.