Which of the following compounds has the lowest melting point? 

• CaBr₂

• CaI₂

• CaF₂

• CaF₂

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

• Ca(OCl)₂

• CaO₂Cl

• CaCl₂

• CaCl₂

On heating which of the following releases CO₂ most easily?

• K₂CO₃

• Na₂CO₃

• MgCO₃

• MgCO₃

What is the value of electron gain enthalpy of Na⁺ if IE₁ of Na = 5.1 eV?

• -5.1 eV

• -10.2 eV

• +2.55 eV

• +2.55 eV

Match (I) with list (II) for the  compositions of substances and select the correct answer using the code given below the lists.

• A	B	C	D
  3	4	1	2

• A	B	C	D
  2	3	4	1

• A	B	C	D
  1	2	3	5

• A	B	C	D
  1	2	3	5

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

• the solubility of their hydroxides in water

• the solubility of their sulphates in water

• ionisation energy 

• ionisation energy 

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

• CaSO₄

• BeSO₄

• BaSO₄

• BaSO₄

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

• MCl> MI>MBr>MF

• MF> MCl> MBr>MI

• MF > MCl> MI>MBr

• MF > MCl> MI>MBr

179.

The alkali metals form salt-like hydrides by the direct synthesis at elevated temperature. The thermal stability of these hydrieds decreases in which of the following orders?

• CsH > RbH > KH > NaH >LiH

• KH > NaH> LiH > CsH >RbH

• NaH > LiH >KH> RbH> CsH

• NaH > LiH >KH> RbH> CsH

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

• BeCO₃ < MgCO₃ < K₂CO₃ <CaCO₃

• BeCO₃ < MgCO₃ < CaCO₃ <K₂CO₃

• MgCO₃ < BeCO₃ < CaCO₃ < K₂CO₃

• MgCO₃ < BeCO₃ < CaCO₃ < K₂CO₃