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

• H₃PO₄, H₃PO₃

• H₃PO₅, H₄P₂O₇

• H₃PO₃, H₃PO₂

• H₃PO₂, HPO₃

$\mathrm{Cl}-\mathrm{P}-\mathrm{Cl}$ bond angles in PCl₅ molecule are

• 120° and 90°

• 60° and 90°

• 60° and 120°

• 120° and 30°

Hair dyes contain

• copper nitrate

• gold chloride

• silver nitrate

• copper sulphate

Which of the following compounds volatilises on heating?

• MgCl₂

• HgCl₂

• CaCl₂

• FeCl₃

AgCl dissolves in a solution of NH₃ but not in water because :

• NH₃ is a better solvent than H₂O

• Ag⁺ forms a complex ion with NH₃

• NH₃  is a stronger base than H₂O

• the dipole moment of water is higher than NH₃

Pnicogens are the elements of group

• 15

• 13

• VIII

• Zero

Which one of the following forms vortex ring ?

• P₂O₅

• PH₃

• NH₃

• P₄O₁₀

What is the product formed when acetylene reacts with hypochlorous acid ?

• CH₃COCl

• ClCH₂CHO

• Cl₂CHCHO

• ClCH₂COOH

849.

As the number of -OH groups increases in hypophosphorus acid, phosphorus acid and phosphoric acid, the acidic strength

• increases

• decreases

• remains nearly same

• remains appropriately same

The comparatively high b.pt. of HF is due to

• high reactivity of fluorine

• small size of hydrogen atom

• formation of hydrogen bonds and consequent association

• high IE of fluorine