14 th group elements (p-block) practice · Medium

Which gas is liberated when $\mathrm{A}{\mathrm{l}_4}{\mathrm{C}_3}$ is hydrolysed?

Statement (S): Band gap in germanium is small.

Explanation (E): The energy spread of each germanium atomic energy level is infinitesimally small.

Assertion (A) : ${PbCl}_2$ is more stable than ${PbCl}_4$.

Reason (R) : ${PbCl}_4$ is powerful oxidising agent.

The calorific value of carbon is about ……. kcal.

Which is pseudo solid?

Which of the following is not true for boron and aluminium?

A fibrous mineral which can withstand red hot flames without any damage is

Carbon dioxide dissolves under pressure in water to give:

Consider the equilibrium, $C(s) + {H_2}O(g)\underset{{}}{\overset{{}}{\leftrightharpoons}}CO(g) + {H_2}(g)$ Which of the following statements is true at equilibrium?

An aqueous solution of a substance gives a white precipitate on treatment with dil HCl, which dissolved on heating. On passing ${\mathrm{H}_2}\mathrm{S}$ in hot acidic solution a black precipitate is formed. The substance is:

Choose the incorrect statement :

a. In diamond each c-atom undergoes $\mathrm{s p}^3$ hybridisation.

b. In graphite each layer is composed of planer hexagonal rings with $\mathrm{s p}^3$ hybridized $\mathrm{c}$-atom

c. Fullerenes are made by heating of graphite in an electric arc in presence of inert gases.

d. Max. percentage of carbon is present in anthracite between diffrent form of coal.

On strong heating lead nitrate gives:

The refractive index of diamond is highest among solids. Its value is:

(A): ${CO}_2$ and ${SiO}_2$ have same physical state at room temperature.

(R): ${CO}_2$ does not contains ${C}={O}$ bonds, ${SiO}_2$ does not contain ${Si}={O}$ bonds.

Feldspar is:

Lewis acids among the following are
$\begin{array}{cccccccccccccccccccc} {\left( {\text{a}} \right)\,\,CC{l_4}}&{\left( {\text{b}} \right)\,\,SiC{l_4}}&{\left( {\text{c}} \right)\,\,Ge{F_4}} \end{array}$

Carbon dioxide turns:

In the sale of diamonds the unit of weight is carat. One carat is equal to:

The major component/ingredient of Portland cement is

Which of the following is the amorphous form of silica used in filtration plants?

The small increase in the covalent radii from $\mathrm{Si}$ to $\mathrm{Pb}$ is due to the presence of

Which fuel has the highest calorific value?

Which of the following has the minimum heat of dissociation?

Select Incorrect reaction ?

What is the state of hybridization of carbon in fullerene?

$\mathrm{Si}{\mathrm{H}_4} + {\mathrm{O}_2}$ mixture on bubbling through water and bubbles coming in contact with air:

Select correct statement(s).

The blue coloured mineral ‘Lapis Lazuli’ used as semiprecious stone is:

If $\mathrm{C}(\text {diamond})\rightarrow \mathrm{C}(\text {graphite})+\mathrm{X} \mathrm{~kJ} \mathrm{~mol}^{-1}$

$\begin{aligned} & \mathrm{C}(\text {diamond})+\mathrm{O}_2(\mathrm{g}) \rightarrow \mathrm{CO}_2(\mathrm{g})+\mathrm{Y} \mathrm{~kJ} \mathrm{~mol}^{-1} \\ & \mathrm{C}(\text {graphite})+\mathrm{O}_2(\mathrm{g}) \rightarrow \mathrm{CO}_2(\mathrm{g})+\mathrm{Z~kJ} \mathrm{~mol}^{-1} \end{aligned}$

At constant temperature. Then

The anion present in the cyclic structure of silicates is