Uses of Calcium Sulphate

Q.

What are the uses of Plaster of Paris?

Q.

The chemical formula of plaster of Paris is

1. ${\mathrm{CaSO}}_4.2{\mathrm{H}}_2\mathrm{O}$

2. ${\mathrm{CaSO}}_4.\mathrm{H}2\mathrm{O}$

3. ${\mathrm{CaSO}}_4.\frac{1}{2}{\mathrm{H}}_2\mathrm{O}$

4. $2{\mathrm{CaSO}}_4.{\mathrm{H}}_2\mathrm{O}$

Q. Portland cement contains $\text{X}$ to enhance the setting time. What is $\text{X}$?

1. ${\text{CaSO}}_4$
2. ${\text{CaSO}}_4\cdot \frac{1}{2}{\text{H}}_2\text{O}$
3. ${\text{CaSO}}_4\cdot 2{\text{H}}_2\text{O}$
4. ${\text{CaCO}}_3$

Q.

The correct formula for barium sulfate is

1. $\mathrm{BaS}$

2. ${\mathrm{BaSO}}_2$

3. $\mathrm{BaSO}$

4. ${\mathrm{BaSO}}_4$

Q.

Is Plaster of Paris waterproof?

Q. Setting of plaster of paris involves:

1. Oxidation with atmospheric oxygen
2. Combination with atmospheric $C{O}_2$
3. Dehydration
4. Hydration to yield another hydrate

Q.

Define:

Plaster of paris

Q. The chemical formula for gypsum is :

1. $CaS{O}_4$
2. $CaS{O}_4.2H_{2}O$
3. $CaS{O}_4.H_{2}O$
4. $2CaS{O}_4.3H_{2}O$
   

Q.

Why Should Plaster of Paris be stored in air-tight containers?

Q.

Describe the importance of the following: (i) limestone (ii) cement (iii) plaster of paris.

Q. The difference in the number of water molecules in gypsum and plaster of paris is:

1. $\frac{1}{5}$
2. $2$
3. $\frac{1}{2}$
4. $1\frac{1}{2}$

Q. Plaster of paris is prepared from

1. Quick lime
2. Slacked lime
3. Gypsum
4. Lime stone

Q. Identify the correct statement

1. Plaster of paris is obtained by heating gypsum
2. Gypsum is obtained by heating plaster of paris
3. Plaster of paris is obtained by partial oxidation of gypsum
4. Plaster of paris can be obtained by hydration of gypsum

Q. Give chemical name, formula, and uses of Plaster of Paris.

Q. Plaster of paris is obtained by heating gypsum at controlled-temperature.

1. True
2. False

Q. Write the chemical names and formulae of plaster of pairs and gypsum.

Q. The molecular formula of gypsum is :

1. $CaS{O}_4.H_{2}O$
2. $CaS{O}_4.2H_{2}O$
3. $2CaS{O}_4.H_{2}O$
4. $CaS{O}_4.3H_{2}O$

Q. Plaster of Paris should be stored in moisture -proof container. Explain why.

Q. Plaster of Paris is obtained by heating:

1. sodium carbonate
2. calcium sulphate
3. gypsum
4. limestone

Q. Write the method of preparation, chemical name and chemical formula of Plaster of Paris.

Q. Chemical formula of epsom salt is $CaS{O}_4.2H_{2}O$

1. True
2. False

Q.

Is Plaster of Paris used for walls?

Q. Plaster of paris is

1. CaSO₄ . H₂O

2. CaSO₄ .2H₂O

3. 2CaSO₄ . H₂O

4. CaSO₄ . 3H₂O

Q. Plaster of paris is

1. $CaS{O}_4.2H_{2}O$
2. $CaS{O}_4.3H_{2}O$
3. $CaS{O}_4.H_{2}O$
4. $CaS{O}_4.\frac{1}{2}{H}_{2}O$

Q. The difference of number of water molecules in gypsum and plaster of paris is

1. 
2. 
3. 
4. 

Q. Plaster of paris hardens by :

1. changing into carbonate
2. uniting with water
3. giving $C{O}_2$
4. giving out water

Q. Hydrated calcium sulphate when heated at 120-${130}^{0}C$ loses ______.

1. $3/2H_{2}O$
2. $1/2H_{2}O$
3. $H_{2}O$
4. 2$H_{2}O$

Q.

Match the compounds given in Column I with their uses mentioned in Column II
$\begin{array}{cc}ColumnI& ColumnII\\ A.CaC{O}_3& 1.Dentistry,ornamentalwork\\ B.Ca(OH{)}_2& 2.Manufactureofsodiumcarbonate\\ C.CaO& 3.Manufactureofhighqualitypaper\\ D.CaS{O}_4& 4.Usedinwhitewashing\end{array}$

Q. The final product of setting of plaster of paris is _________.

1. gypsum
2. anhydrite
3. mortar
4. cement

Q. Gypsum, $CaS{O}_4.2H_{2}O$, on heating to about ${120}^{0}C$ forms a compound which has the chemical composition represented by

1. $2CaS{O}_4.H_{2}O$
2. $CaS{O}_4.H_{2}O$
3. $CaS{O}_4$
4. $2CaS{O}_4.3H_{2}O$