p- BLOCK JEE

What may be expected to happen when phosphine gas is mixed with chlorine gas?

(1) The mixture only cools down

(2) PCl₃ and HCl are formed and the mixture warms up

(3) PCl₅ and HCl are formed and the mixture cools down

(4) PH₃·Cl₂ is formed with warming up.

• 1

• 2

• 3

• 4

Chlorine water on standing loses its colour and forms:-

(1) HCl and HClO₂

(2) HCl only

(3) HOCl and HOCl₂

(4) HCl and HOCl

• 1

• 2

• 3

• 4

Example of a three-dimensional silicate is :

(1) Beryls

(2) Zeolites

(3) Feldspars

(4) Ultramarines

• 1

• 2

• 3

• 4

The gas evolved on heating CaF₂ and SiO2 with concentrated H₂SO₄, on hydrolysis gives a white gelatinous precipitate. The precipitate is:

(1) silica gel

(2) silicic acid

(3) hydrofluosilicic acid

(4) calcium fluorosilicate

• 1

• 2

• 3

• 4

The amorphous form of silica is

(1) cristobalite

(2) kieselguhr

(3) tridymite

(4) quartz.

• 1

• 2

• 3

• 4

Which of the following statements regarding sulphur is incorrect?

(1) At 600⁰ the gas mainly consists of S₂ molecules

(2) The oxidation state of sulphur is never less than +4 in its compounds

(3) S₂ molecule is paramagnetic

(4) The vapour at 200⁰ C consists mostly of S₈ rings

• 1

• 2

• 3

• 4

Boron cannot form which one of the following anions?

(1) B(OH)₄^–

(2) BO₂^–

(3) BF₆^3-

(4) BH₄^–

• 1

• 2

• 3

• 4

Which of the following statements is wrong?

(1) Single N–N bond is weaker than the single P–P bond

(2) N₂O₄ has two resonance structures

(3) The stability of hydrides decreases from NH3 to BiH3 in group 15 of the periodic table

(4) Nitrogen cannot form d pi – p pi bond

• 1

• 2

• 3

• 4

Assertion: Among the carbon allotropes, diamond is an insulator, whereas, graphite is a good conductor of electricity.

Reason: Hybridization of carbon in diamond and graphite are sp³ and sp², respectively.

(1) Both assertion and reason are correct, but the reason is not the correct explanation for the assertion.

(2) Both assertion and reason are correct, and the reason is the correct explanation for the assertion.

(3) Both assertion and reason are incorrect.

(4) Assertion is an incorrect statement, but the reason is correct.

• 1

• 2

• 3

• 4

Which one of the following reactions of Xenon compounds is not feasible?

(1) 2XeF₂ + 2H₂O → 2Xe +4HF +O₂

(2) XeF₆ + RbF → Rb[XeF₇]

(3) XeO₃ + 6HF → XeF₆ + 3H₂O

(4) 3XeF₄ + 6H₂O → 2Xe +XeO₃ +12HF+1.5O₂

• 1

• 2

• 3

• 4