31 Year NEET Previous Year Questions: The p-Block Elements (Group 13 & 14) - NEET MCQ

Potash Alum, K₂SO₄. Al₂(SO₄). 24H₂O is a double salt.

SiCl₄ gets hydrolysed in moist air and gives white fumes which are used as a smoke screen in warfare.

Glass is a super cooled liquid.

In diamond each carbon atom is sp 3 hybridized and thus forms covalent bonds with four other carbon atoms lying at the corners of a regular tetrahedron.

Water gas is made by blowing steam through the layer of  incandescent coal.

Chlorine is prepared commercially by the electrolysis of an aqueous solution of sodium chloride. It is mainly used as a bleaching agent, bacteriocide and an industrial chemical.

H₃BO₃ is a weak monobasic acid.

In graphite, each carbon is sp² -hybridized and the single occupied unhybridized porbitals of C-atoms overlap side wise to give π -electron cloud which is delocalized and thus the electrons are spread out between the structure.

The correct answer is option B
Common glass consists of silica (SiO₂​). When HF reacts with silica it will form H₂​SiF_6​ or SiF₄​. Both can soluble in water which means that a fresh surface of SiO₂​ will be exposed to attack by HF.

Zeolites are aluminosilicates having three dimensional open structure in which four or six membered rings predominates. Thus, due to open chain structure, they have cavities and can take up water and other small molecules.

Al₂O₃ can be converted to anhydrous AlCl₃ by heating a mixture of Al₂O₃ and carbon in dry Cl₂

Hydrolysis of substituted chlorosilanes yield corresponding silanols which undergo polymerisation.

Polymerisation of dialkyl silandiol yields linear thermoplastic polymer.

A molecule is said to be a lewis acid if it can accept a lone pair.

When the halide is more electronegative the interelectronic repulsion increases making the molecule difficult to accept a lone pair.

 Size of halide also behaves in the same way. Also the degree of hydrolysis increases from fluorine to iodine,so the lewis acidic character increases in the same order.

So,the order of lewis acidity is BBr₃​ > BCl₃​ > BF₃​.

Fused alumina (Al₂O₃) is a bad conductor of electricity. Therefore, cryolite (Na₃AlF₆) and fluorspar (CaF₂) are added to purified alumina which not only make alumina a good conductor of electricity but also reduce the melting point of the mixture to around 1140 K.

Boron nitride (BN) is known as inorganic graphite. The most stable form is hexagonal one. It has layered structure similar to graphite.

Since Me₃SiCl contains only one Cl, therefore it can’t form high molecular mass silicon polymer. It can form only dimer.

SiO₄^4– is basic structural unit of silicates.

Feldspars are 3-dimensional aluminosilicates.