Science (English Medium) Class 12 - CBSE Question Bank Solutions for Chemistry

Write chemical equations of the following reaction :
Benzoyl chloride is hydrogenated in the presence of `"Pd"/(BaSO_4)`

Write a chemical equation for the following reaction: 
Propanone is treated with dilute Ba( OH)₂.

Account for the following : 
t-butyl chloride on heating with sodium methoxide gives 2-methylpropene instead of t-butyl methyl ether.

Write the hybridization and magnetic character of the following complexes:
[Fe(H₂O)₆]²⁺
(Atomic no. of Fe = 26)

Write the hybridization and magnetic character of the following complexes:
[Fe(CO)₅]
(Atomic no. of Fe = 26)

An element crystallizes in fcc lattice with a cell edge of 300 pm. The density of the element is 10.8 g cm⁻³. Calculate the number of atoms in 108 g of the element.

Williamson's synthesis of preparing dimethyl ether is a/an ____________.

Substances that alter the rate of a chemical reaction without being used up in a chemical reaction is known as ____________.

The colligative property is not represented by ____________.

Which two of the following salts are used for preparing iodized salt?

(i) KIO₃

(ii) KI

(iii) I₂

(iv) HI

Which of the following cannot be made by using Williamson Synthesis:

Dehydration of alcohol to ethers is catalysed by:

Assertion: Aryl iodides can be prepared by reaction of arenes with iodine in the presence of an oxidising agent.

Reason: Oxidising agent oxidises I₂ into HI.

\[\ce{(CH3)3CONa + CH3CH2Cl ->[-NaCl] (CH3)3COC2H5}\] is called:

A unit cell of NaCl has 4 formula units. Its edge length is 0.50 nm. Calculate the density if molar mass of NaCl = 58.5 g/mol.

Colligative properties depend on ______.

Colligative properties are observed when:

(i) a non volatile solid is dissolved in a volatile liquid.

(ii) a non volatile liquid is dissolved in another volatile liquid.

(iii) a gas is dissolved in non volatile liquid.

(iv) a volatile liquid is dissolved in another volatile liquid.

Why is the mass determined by measuring a colligative property in case of some solutes abnormal ? Discuss it with the help of Van’t Hoff factor.

Which of the following expressions is correct for the rate of reaction given below?

\[\ce{5Br^- (aq) + BrO3^- (aq) + 6H^+ (aq) -> 3Br2 (aq) + 3H2O(l)}\]

In a reaction, catalyst changes:

(i) physically

(ii) qualitatively

(iii) chemically

(iv) quantitatively