Which of the following compounds has the lowest melting point?

1.  ${\mathrm{CaBr}}_2$

2.  ${\mathrm{Cal}}_2$

3.  ${\mathrm{CaF}}_2$

4.  ${\mathrm{CaCl}}_2$

Which of the following alkaline earth metal sulphates has hydration enthalpy higher than the lattice enthalpy?

1. ${\mathrm{CaSO}}_4$

2. Mg${\mathrm{SO}}_4$

3. ${\mathrm{BaSO}}_4$

4. ${\mathrm{SrSO}}_4$

Property of the alkaline earth metals that increases with their atomic number

1. Solubility of their hydroxides in water

2. Solubility of their sulphates in water

3. Ionization energy

4. Electro-negativity

In the case of alkali metals, the covalent character decreases in the order

1. MCl>Ml>MBr>MF

2. MF>MCl>MBr>Ml

3. MF>MCl>Ml>MBr

4. Ml>MBr>MCl>MF

The correct order of increasing thermal stability of K₂CO₃, MgCO₃, CaCO₃ and BeCO₃ is :

1. ${\mathrm{BeCO}}_3<{\mathrm{MgCO}}_3<{\mathrm{K}}_2{\mathrm{CO}}_3<{\mathrm{CaCO}}_3$

2. ${\mathrm{BeCO}}_3<{\mathrm{MgCO}}_3<{\mathrm{CaCO}}_3<{\mathrm{K}}_2{\mathrm{CO}}_3$

3. ${\mathrm{MgCO}}_3<{\mathrm{BeCO}}_3<{\mathrm{CaCO}}_3<{\mathrm{K}}_2{\mathrm{CO}}_3$

4. ${\mathrm{K}}_2{\mathrm{CO}}_3<{\mathrm{MgCO}}_3<{\mathrm{CaCO}}_3<{\mathrm{BeCO}}_3$

The gas released when baking soda is mixed with vinegar is 

1. CO

2. CO₂

3. CH₄

4. O₂

When treated with conc. HCl, MnO₂ yields a gas (X) which further reacts with Ca(OH)₂ to generate a white solid (Y). The solid Y reacts with dil. HCl to produce the same gas X. The solid Y is                                     

1. CaO

2. CaCl₂

3. Ca(OCl)Cl

4. CaCO₃

The thermal stability of alkaline earth metal carbonates-MgCO₃, CaCO₃, SrCO₃ and BaCO₃, follows the order.                               

1. BaCO₃>SrCO₃>CaCO₃>MgCO₃

2. CaCO₃>SrCO₃>BaCO₃>MgCO₃

3. MgCO₃>CaCO₃>SrCO₃>BaCO₃

4. SrCO₃>CaCO₃>MgCO₃>BaCO₃

CO₂ is passed through lime water. Initially the solution turns milky and then becomes clear upon continued bubbling of CO₂. The clear solution is due to the formation of                                                                  

1. CaCO₃

2. CaO

3. Ca(OH)₂

4. Ca(HCO₃)₂

The most abundant metal  ion present in the human body is 

1. Zn²⁺

2. Ca²⁺

3. Na⁺

4. Fe²⁺