Chemistry in Everyday Life — Chemistry STD 12 Science — Question

Statement $I$: The boiling point of hydrides of Group $16$ elements follow the order

$\mathrm{H}_2 \mathrm{O}>\mathrm{H}_2 \mathrm{Te}>\mathrm{H}_2 \mathrm{Se}>\mathrm{H}_2 \mathrm{~S}$.

Statement $II$: On the basis of molecular mass, $\mathrm{H}_2 \mathrm{O}$ is expected to have lower boiling point than the othe members of the group but due to the presence of extensive $\mathrm{H}$-bonding in $\mathrm{H}_2 \mathrm{O}$, it has higher boiling point.

In the light of the above statements, choose the correct answer from the options given below:

Statement $I$: Aqueous solution of $K _2 Cr _2 O$, is preferred as a primary standard in volumetric analysis over $Na _2 Cr _2 O$, aqueous solution

Statement $II:$ $K _2 Cr _2 O$, has a higher solubility in water than $Na _2 Cr _2 O _7$

In the light of the above statements, choose the correct answer from the options given below:

$(A)$ Dinitrogen is a diatomic gas which acts like an inert gas at room temperature.

$(B)$ The common oxidation states of these elements are $-3,+3$ and +5 .

$(C)$ Nitrogen has unique ability to form $\mathrm{p} \pi-\mathrm{p} \pi$ multiple bonds.

$(D)$ The stability of +$5$ oxidation states increases down the group.

$(E)$ Nitrogen shows a maximum covalency of $6$.

Choose the correct answer from the options given below.