Calcium and Its Compounds

Q. Is plaster of Paris a compound or a mixture

Q. At high temperature, nitrogen combines with calcium carbide to give

1. Calcium cyanamide
2. Calcium carbonate
3. Calcium nitride
4. Calcium cyanide

Q.

Which of the following substance is used as dehydrating agent in laboratory

1. Sodium carbonate

2. Calcium chloride

3. Sodium chloride

4. Potassium nitrate

Q.

Which of the following is present as an active ingredient in bleaching powder for bleaching action?

1. $Ca(OCl{)}_2$

2. $Ca{O}_{2}Cl$

3. $CaC{l}_2$

4. $CaOC{l}_2$

Q.

$\begin{array}{cc}\text{List I}& \text{List II}\\ \text{1. Plaster of Paris}& \text{a.}CaS{O}_4.2H_{2}O\\ \text{2. Epsomite}& \text{b.}CaS{O}_4.1/2H_{2}O\\ \text{3. Kieserite}& \text{c.}MgS{O}_4.7H_{2}O\\ \text{4. Gypsum}& \text{d.}MgS{O}_4.H_{2}O\\ & \text{e.}CaS{O}_4\end{array}$

1. 1 - a; 2 - b; 3 - c; 4 - e

2. 1 - b; 2 - c; 3 - d; 4 - a;

3. 1 - b; 2 - d; 3 - c; 4 - a;

4. 1 - a; 2 - c; 3 - d; 4 - b;

Q.

How is plaster of paris obtained ? What reaction is involved in the setting of a paste of plaster of paris? What is it used for? [3 MARKS]

Q. Choose the correct option depicting the correct match of the given chemical changes and their characteristic.

Change	Characteristics
$1.{\mathrm{NaHCO}}_3\left(s\right)+{\mathrm{CH}}_3\mathrm{COOH}\left(l\right)\to {\mathrm{CO}}_2\left(g\right)+H_{2}O\left(l\right)+{\mathrm{CH}}_3\mathrm{COONa}\left(\mathrm{aq}\right)$	A.Formation of precipitate
$2.\mathrm{Fe}\left(s\right)+{\mathrm{CuSO}}_4\left(\mathrm{aq}\right)\to {\mathrm{FeSO}}_4\left(\mathrm{aq}\right)+\mathrm{Cu}\left(s\right)$	B.Evolution of gas
$3.{\mathrm{BaCl}}_2\left(\mathrm{aq}\right)+{\mathrm{Na}}_2\mathrm{SO}4\left(\mathrm{aq}\right)\to {\mathrm{BaSO}}_4\left(s\right)+2\mathrm{NaCl}\left(\mathrm{aq}\right)+{\mathrm{BaSO}}_4\left(\mathrm{ppt}\right)$	C.Change in colour

1. 1-B; 2-C and 3-A
2. 1-A; 2-B and 3-C
3. 1-B; 2-A and 3-C
4. 1-C; 2-B and 3-A

Q.

What are the five uses of Plaster of Paris? [5 MARKS]

Q. A small amount of $CaC{O}_3$ completely neutralizes 525 ml of 0.1 N HCI and no acid is left at the end. After converting all calcium chloride to $CaS{O}_4,$ how much plaster of Paris can be obtained?

1. 1.916 g
2. 5.827 g
3. 3.81 g
4. 3.57 g

Q. Question 5
Write an equation to show the reaction between Plaster of Paris and water.