MHT CET 2018 :: Chemistry :: General questions

• Chemistry - General questions

in which among the following solids, Schottky defect is not observed?

Answer:

Explanation:

The schottky defect is shown by those compounds in which the cations and anions are of almost similar sizes. Therefore, CsCl, KCl and NaCl will show  Schottky  defect while ZnS will not show this defect due to the large difference in the size of anion and cation

Note: ZnS will show Frenkel defect

Which is the SI unit of density?

Answer:

Explanation:

Density of a substance is defined as its amount of mass per unit volume. So, SI  unit of density can be obtained by using the following relation.

SI unit of density = SI unit of mass/ SI unit of volume =  $\frac{kg}{m^{3}} $ or kg m^-3

Which of the following is most reactive towards the addition reaction of hydrogen cyanide to form the corresponding cyanohydrin?

Answer:

Explanation:

Formaldehyde (HCHO) is most reactive towards the addition reaction of hydrogen cyanide because it is least sterically hindered.

 The order of reactivity towards  addition of hydrogen cyanide is a follows:

 Note: In case of ketones, only  acetone, butanone , pentan-3-one and pinacolone form cyanohydrin .The failure with bulky ketones is largely  due to steric  effects.

 What is the number of donar atoms in dimethylglyoximato ligand?

Answer:

Explanation:

 Dimethylglyoximato ligand is a bidentate ligand, i.e, it can bind with metal ion through two donor atoms.

Which of the following is a tricarboxylic acid?

Answer:

Explanation:

 Malonic acid, succinic acid and malic acid are dicarboxylic acids while citric acid is a tricarboxylic acid. The respective structures of the following acids are given below.

• Chemistry - General questions