When H₂S is passed through Hg₂S we get

Arrange the following in order of property indicated for each set : ${\mathrm{H}}_2\mathrm{O} {\mathrm{H}}_2\mathrm{S} {\mathrm{H}}_2\mathrm{Se} {\mathrm{H}}_2\mathrm{Te}$ – increasing acidic character

Give reason :

Hydrogen bonding in ${\mathrm{H}}_2\mathrm{O}$ but not in ${\mathrm{H}}_2\mathrm{S}$.

In which one of the following arrangements the given sequence is not strictly according to the properties indicated against it?

Explain the hydrides of oxygen family under the following point : 

Acidic property

Explain the hydrides of oxygen family under the following point : 

Reducing property

Explain the hydrides of oxygen family under the following point : 

Thermal stability