Which of the following statements is true?

• H₃PO₃ is a stronger acid than H₂SO₃

• In aqueous medium HF is a stronger acid than HCl

• HClO₄ is a weaker acid than HClO₃

• HClO₄ is a weaker acid than HClO₃

What products are expected from the disproportionation reaction of hypochlorous acid?

• HClO₃ and Cl₂O 

• HClO₂ and HClO₄

• HCl and Cl₂O

• HCl and Cl₂O

Which of the following oxides is amphoteric in character?

• CaO

• CO₂

• SiO₂

• SiO₂

The molecular shapes of SF₄, CF₄ and XeF₄ are

• the same with 2,0 and 1 lone pairs of electrons on the central atom, respectively

• the same with 1, 1 and 1 lone pair of electrons on the central atoms, respectively

• different with 0, 1 and 2 lone pair of electrons on the central atoms, respectively

• different with 0, 1 and 2 lone pair of electrons on the central atoms, respectively

The number of hydrogen atom(s) attached to phosphorus atom in hypophosphorous acid is

• zero

• Two

• one

• one

The correct order of the thermal stability of hydrogen halides (H – X) is

• HI > HBr > HCl > HF

• HF > HCl > HBr > HI

• HCl < HF > HBr < HI

• HCl < HF > HBr < HI

Heating an aqueous solution of aluminium chloride to dryness will give

• AlC_l3

• Al₂Cl₆

• Al₂O₃

• Al₂O₃

In silicon dioxide

• Each silicon atom is surrounded by four oxygen atoms and each oxygen atom is bonded to two silicon atoms

• Each silicon atom is surrounded by two oxygen atoms and each oxygen atom is bonded to two silicon atoms

• Silicon atoms is bonded to two oxygen atoms

• Silicon atoms is bonded to two oxygen atoms

219.

Which one the following statement regarding helium is incorrect?

• It is used to fill gas balloons instead of hydrogen because it is lighter and non – inflammable

• It is used in gas – cooled nuclear reactors

• It is used to produce and sustain powerful superconducting reagents

• It is used to produce and sustain powerful superconducting reagents

One mole of magnesium nitride on the reaction with an excess of water gives

• one mole of ammonia

• two moles of nitric acid

• Two mole of ammonia

• Two mole of ammonia