The function of Fe(OH)₃ in the contact process is :

• to remove arsenic impurity

• to detect colloidal impurity

• to detect colloidal impurity

• to remove dust particles

Assertion : Hydrides of group-16 elements show volatility in the order :

H₂O > H₂S > H₂Se > H₂Te

Reason : Electronegativity of group-16 elements increases down the group from oxygen to tellurium

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion

• If assertion is true but reason is false.

• If both assertion and reason are false

Assertion : Equivalent weight of NH, in the reaction, N, $\to$ NH₃ is 17/3 while that of N₂ is 28/6.

Reason : Equivalent weight = $\frac{\mathrm{Molecular} \mathrm{weight}}{\mathrm{Number} \mathrm{of} {\mathrm{e}}^{-} \mathrm{lost} \mathrm{or} \mathrm{gained} \mathrm{per} \mathrm{mole}}$

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false.

• If both assertion and reason are false

Chlorine oxidises sodium thiosulphate to form

• Na₂SO₃

• Na₂O

• Na₂SO₄

• Na₂CO₃

Which can dissolve I₂ ?

• KI

• NaI

• LiI

• HI

Which of the following can be oxidised by SO₂?

• K₂Cr₂O₇

• Mg

• H₂O

• All of these

Which one of the following is incorrect ?

• Ionisation enthalpy of molecular oxygen is very close to that of Xe

• Only type of interatomic interaction between particles of noble gases are weak dispersion forces

• Hydrolysis of XeF₆ is not a redox reaction

• Xenon fluorides are not reactive

Which one ofthe following nitrogen oxides does not contain N-N bonds?

• N₂O

• N₂O₃

• N₂O₄

• N₂O₅

Assertion : Charcoal is used in separation of noble gases.

Reason : Charcoal has porous structure

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false

• If both assertion and reason are false

Rhombic sulphur dissolves best in

• CS₂

• H₂O

• ethanol 

• ether