Metal carbonates decompose on heating to give metal oxide and carbon dioxide. Which of the metal carbonates is most stable thermally?

1. ${\mathrm{MgCO}}_3$

2. ${\mathrm{CaCO}}_3$

3. ${\mathrm{SrCO}}_3$

4. ${\mathrm{BaCO}}_3$

The solubility of metal halides depends on their nature, lattice enthalpy and hydration enthalpy of the individual ions. Amongst fluorides of alkali metals, the lowest solubility of LiF in water is due to -

1. Ionic nature of lithium fluoride

2. High lattice enthalpy

3. High hydration enthalpy for lithium ion

4. Low ionisation enthalpy of lithium ion

Amphoteric hydroxides react with both alkalies with acids. Which of the following Group 2 metal hydroxides is soluble in sodium hydroxide?

1. $\mathrm{Be}{\left(\mathrm{OH}\right)}_2$

2. $\mathrm{Mg}{\left(\mathrm{OH}\right)}_2$

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

4. $\mathrm{Ba}{\left(\mathrm{OH}\right)}_2$

By adding gypsum to cement

1. Setting time of cement becomes less

2. Setting time of cement increases

3. Colour of cement becomes light

4. Shining surface is obtained

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?

Identify the correct formula of halides of alkaline earth metals from the following.

1.  ${\mathrm{BaCl}}_2·2{\mathrm{H}}_2\mathrm{O}$

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

3.  ${\mathrm{CaCl}}_2·6{\mathrm{H}}_2\mathrm{O}$

4.  ${\mathrm{SrCl}}_2·4{\mathrm{H}}_2\mathrm{O}$

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