The boiling points of hydrides of group 16 are in the order

• (a) H2O > H2Te > H2S > H2Se

• (b) H2O > H2S > H2Se > H2Te

• (c) H2O > H2Te > H2Se > H2S

• (d) None of these

Chalcogens are 

• Group 15 elements
• Group 16 elements
• Group 17 elements
• Group 18 elements

SF₆ is known but SCl₆ is not________

• Due to small size of fluorine six F ^– ion can be accomodated around sulphur whereas chloride ion is comparatively larger in size, therefore, there will be interionic repulsion

• Due to absence of vacant d orbital

• Chlorine have more electron gain enthalpy than

• none of these

Acidity of diprotic acid in aqueous solution increases in the order.

• H2Se < H2Te < H2S

• H2S < H2Se < H2Te

• ) H2Te < H2S < H2Se

• H2Se < H2S < H2Te

H2S is more acidic than H2O because

• oxygen is more electronegative than sulphur.

• atomic number of sulphur is higher than oxygen.

• H — O bond dissociation energy is less also compared to H — S bond.

• H — S bond dissociation energy is less as compared to H — O bond.

What is the oxidation number of Oxygen in OF₂?

• +2

• 0

• +1

• -2

The molecular shape of SF₄ is

• square planar

• see-saw

• tetrahedral

• bent 'T' shape

Which compound is responsible for the smell of rotten eggs in the reaction of conc. sulfuric acid with NaI?

• Iodine vapours

• HI vapours

• SO₂ fumes

• H₂S fumes

Correct order of negative Electron Gain Enthalpy is

• Po < Te < O < Se < S

• O < Po < Te < Se < S

• Po < Te < Se < S < O

• Po < Te < Se < O < S

O₃ acts as a powerful oxidising agent because

• ozone is thermodynamically unstable

• its decomposition into oxygen results in the liberation of heat

• it liberates atoms of nascent oxygen

  (O3 → O2 + O)

• ozone has a characteristic smell