Question

When MgSO4.XH2O crystals were exposed to the atmosphere for several days, there was a loss in mass. What is the name given to this phenomenon?

a) Hydration
b) Sublimation
c) Efflorescence
d) Deliquescence

Answer 1

Efflorescence is the phenomenon where MgSO4.XH2O crystals lose mass when exposed to the atmosphere due to sublimation.

Step-by-step explanation:

The phenomenon where MgSO4.XH2O crystals lose mass when exposed to the atmosphere is called efflorescence.

Efflorescence occurs when hydrated crystals lose their water of hydration (XH2O), leaving behind a dry, powdery substance. It happens due to the process of sublimation, where the solid crystals directly convert into a gas without becoming a liquid first.