Plaster of Paris should be stored in a moisture-proof container. Why?

AcademicChemistryNCERTClass 10

Plaster of Paris should be stored in a moisture-proof container because the Plaster of Paris, a powdery mass, absorbs water (moisture) from the environment to form a hard solid substance known as Gypsum.
Plaster of pairs + water → Gypsum

$CaSO_{4} .\frac{1}{2} H_{2} O+1\frac{1}{2} H_{2} O\rightarrow CaSO_{4} .2H_{2} O$

[Extra information: pH stands for "power of hydrogen".The "H" is capitalized because it is the hydrogen element symbol. 
Acidic and basic are two extremes that describe a chemical property chemical. The pH scale measures how acidic or basic a substance is. 
  • The pH scale ranges from 0 to 14.
  • A pH less than 7 is acidic in nature.
  • A pH of 7 is neutral.
  • A pH greater than 7 is basic in nature.
pH decreases with an increase in temperature. This does not mean that the water becomes more acidic at higher temperatures. A solution is considered acidic if there is an excess of hydrogen ions (H) over hydroxide ions (OH-).]
Updated on 10-Oct-2022 12:46:30