391.

When excess of NaOH solution is added to aqueous solution of iodine, the colour of solution becomes

• blue

• yellow

• colourless

• pale green

Which of the following compounds has the lowest melting point?

• CaBr₂

• Cal₂

• CaF₂

• CaCl₂

Which of the following metal carbonates decomposes on heating?

• MgCO₃

• Na₂CO₃

• K₂CO₃

• Rb₂CO₃

Ammonia gas can be dried over

• CaCl₂

• conc. H₂SO₄

• P₂O₅

• quick lime

Which of the following carbonates decomposes readily at low temperatures ?

• Na₂CO₃

• K₂CO₃

• Li₂CO₃

• Rb₂CO₃

Plaster of paris is

• CaSO₄.$\frac{1}{2}$H₂O

• CaSO₄.2H₂O

• CaSO₄.H₂O

• CaSO₄.4H₂O

Bleaching powder is obtained by treating Cl₂ with

• Ca(OH)₂

• CaO

• CaCO₃

• CaCl₂

The solubility of carbonates decreases below the magnesium group due to decrease in:

• Lattice energies of solids

• inter-ionic attraction

• hydration energies of cations

• entropy of solution formation

What is the formula of bleaching powder?

• CaO(OCl)

• Ca(OCl)Cl

• Ca(OCl)₂

• Ca(OCl)₂Cl

Which of the following statements is false ?

• CaOCl₂ gives OH^- Cl^- and OCl^- in aqueous solution

• Diamond and graphite are allotropes of carbon

• Bleaching action of Cl₂ in moist condition is not permanent

• Calomel is Hg₂Cl₂