Chemical Formula

Step 1: Understand Plaster of Paris.
Plaster of Paris is a form of calcium sulfate hemihydrate, which is obtained by heating gypsum (

%5Ctext%7BCaSO%7D_4%20%5Ccdot%202%5Ctext%7BH%7D_2%5Ctext%7BO%7D

). Its chemical formula is:

%5Ctext%7BCaSO%7D_4%20%5Ccdot%20%5Cfrac%7B1%7D%7B2%7D%20%5Ctext%7BH%7D_2%5Ctext%7BO%7D.

Step 2: Analyze Each Option.
Option (1):

%5Ctext%7BCaSO%7D_4

— Incorrect, as this is the formula for anhydrous calcium sulfate, not plaster of Paris.
Option (2):

%5Ctext%7BCaSO%7D_4%20%5Ccdot%20%5Cfrac%7B1%7D%7B2%7D%20%5Ctext%7BH%7D_2%5Ctext%7BO%7D

— Correct, as this matches the formula for plaster of Paris.
Option (3):

%5Ctext%7BCaSO%7D_4%20%5Ccdot%20%5Ctext%7BH%7D_2%5Ctext%7BO%7D

— Incorrect, as this is the formula for gypsum, not plaster of Paris.
Option (4):

%5Ctext%7BCaSO%7D_3

— Incorrect, as this is the formula for calcium sulfite, not plaster of Paris. Step 3: Final Answer.

%5Cboxed%7B(2)%20%5Cquad%20%5Ctext%7BCaSO%7D_4%20%5Ccdot%20%5Cfrac%7B1%7D%7B2%7D%20%5Ctext%7BH%7D_2%5Ctext%7BO%7D%7D

Chapter Questions
1 MCQs