Dead burnt plaster is-

1. ${\mathrm{CaSO}}_4$

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

3. ${\mathrm{CaSO}}_4·{\mathrm{H}}_2\mathrm{O}$

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

Suspension of slaked lime in water is known as

1. Lime water

2. Quick lime

3. Milk of lime

4. Aqueous solution of slaked lime

Which of the following elements does not form hydride by direct heating with dihydrogen?

1. Be

2. Mg

3. Sr

4. Ba

The formula of soda ash is

1.  ${\mathrm{Na}}_2{\mathrm{CO}}_3·10{\mathrm{H}}_2\mathrm{O}$

2.  ${\mathrm{Na}}_2{\mathrm{CO}}_3·2{\mathrm{H}}_2\mathrm{O}$

3.  ${\mathrm{Na}}_2{\mathrm{CO}}_3·{\mathrm{H}}_2\mathrm{O}$

4.  ${\mathrm{Na}}_2{\mathrm{CO}}_3$

A substance which gives brick red flame and breaks down on heating to give oxygen and a brown gas is

1. Magnesium nitrate

2. Calcium nitrate

3. Barium nitrate

4. Strontium nitrate

Which of the following statements is true about $\mathrm{Ca}{\left(\mathrm{OH}\right)}_2$?

1. It is used in the preparation of bleaching powder

2. It is a light blue solid

3. It does not possess a disinfectant property

4. It is used in the manufacture of cement

Chemical A is used for the preparation of washing soda to recover ammonia. When CO₂ is bubbled through an aqueous solution of A, the solution turns milky. It is used in whitewashing due to its disinfectant nature. The chemical formula of A is-

1. $\mathrm{Ca}{\left({\mathrm{HCO}}_3\right)}_2$

2. $\mathrm{CaO}$

3. $\mathrm{Ca}{\left(\mathrm{OH}\right)}_2$

4. ${\mathrm{CaCO}}_3$

Dehydration of hydrates of halides of calcium, barium and strontium i.e., ${\mathrm{CaCl}}_2·6{\mathrm{H}}_2\mathrm{O}$, ${\mathrm{BaCl}}_2·2{\mathrm{H}}_2\mathrm{O}$, ${\mathrm{SrCl}}_2·2{\mathrm{H}}_2\mathrm{O}$, can be achieved by heating. 
These become wet on keeping in air. Which of the following statements is correct about these halides?

Metallic elements are described by their standard electrode potential, fusion enthalpy, atomic size, etc. The alkali metals are characterized by which of the following properties?

a. High boiling point

b. High negative standard electrode potential

c. High-density

d. Large atomic size

1. (a, b)
2. (b, c)
3. (c, d)
4. (b, d)

Several sodium compounds find use in industries. Which of the following compounds are used in the textile industry?

a. ${\mathrm{Na}}_2{\mathrm{CO}}_3$

b. ${\mathrm{NaHCO}}_3$

c. $\mathrm{NaOH}$

d. $\mathrm{NaCl}$

Choose the correct option
1. (a, c)
2. (b, c)
3. (c, d)
4. (a, d)