The following are some statements related to VA group hydrides,

(I) Reducing property increases from NH₃ to BiH₃

(II) Tendency to donate lone pair decreases from NH₃ to BiH₃.

(III) Thermal stability of hydrides decreases from  NH₃ to BiH₃.

(IV). Bond angle of hydrides decreases from  NH₃ to BiH₃.

The correct statements are:

• I, II, III and IV

• I, III and IV

• L, II and IV

• I and IV

The type of bonds present in sulphuric anhydride are

• 3σ and three p$\mathrm{\pi }$-d$\mathrm{\pi }$

• 3σ and one p$\mathrm{\pi }$-p$\mathrm{\pi }$ and two p$\mathrm{\pi }$-d$\mathrm{\pi }$

• 2σ and three p$\mathrm{\pi }$-d$\mathrm{\pi }$

• 2σ and two p$\mathrm{\pi }$-d$\mathrm{\pi }$

Which pair of oxyacids of phosphorus contains 'P-H' bonds?

• H₃PO₄, H₃PO₃

• H₃PO₅, H₄P₂O₇

• H₃PO₃, H₃PO₂

• H₃PO₂, HPO₃

The made of nitrogen formed by thermal decomposition of NH₄NO₃ is

• NO

• N₂O

• N₂O₅

• NO₂

Which one of the following is most acidic?

• H₂O

• H₂S

• H₂Te

• H₂Se

Which one of the following is formed apart from sodium chloride when chlorine reacts with hot concentrated sodium hydroxide?

• NaOCl

• NaClO₃

• NaClO₂

• NaClO₄

Helium mixed with oxygen is used in the treatment of

• beri beri

• burning feet

• joints burning

• asthma

Phosgene is formed slowly from which one of the following on exposure to air and sunlight?

• CHCl₃

• H₃CCl

• H₃COH

• C₂H₅Cl

The volume in mL of 0.1 M solution of NaOH required to completely neutralise 100 mL of 0.3 M solution of H₃PO₃ is

• 60

• 600

• 300

• 30

The total number of σ and $\mathrm{\pi }$-bonds in pyrophosphoric acid are respectively

• 8, 2

• 10, 2

• 12, 2

• 8, 4