Science (English Medium) इयत्ता १२ - CBSE Question Bank Solutions

Complete the following reaction sequence.

\[\begin{array}{cc}
\ce{O}\phantom{...............................................}\\
||\phantom{...............................................}\\
\ce{CH3 - C - CH3 ->[(i) CH3MgBr][H2O] (A) ->[Na metal][Ether] (B) ->[CH3 - Br] (C)}
\end{array}\]

Assertion: Formaldehyde is a planar molecule.

Reason: It contains sp² hybridised carbon atom.

Which of the following compound will not undergo azo coupling reaction with benzene diazonium chloride?

The product of the following reaction is:

(i) 

(ii) 

(iii)

(iv)

Which of the following reactions belong to electrophilic aromatic substitution?

(i) Bromination of acetanilide

(ii) Coupling reaction of aryldiazonium salts

(iii) Diazotisation of aniline

(iv) Acylation of aniline

Under what reaction conditions (acidic/basic), the coupling reaction of aryldiazonium chloride with aniline is carried out?

When benzene diazonium chloride reacts with phenol, it forms a dye. This reaction is called ______.

What is ferromagnetism?

Iron (z=26) is highly ferromagnetic. Explain.

What type of magnetism is shown in the following alignment of magnetic moments?

Account for the following: Fluorine does not exhibit positive oxidation state.

Write the major products(s) in the following:

Name the reagents used in the following reactions:

Predict the products of the following reactions:

Fluorine is a stronger oxidising agent than chlorine. Why?

What type of magnetism is shown by a substance if magnetic moments of domains are arranged in same direction?

Why vitamin C cannot be stored in our body?

Compare the oxidizing action of F₂ and Cl₂ by considering parameters such as bond dissociation enthalpy, electron gain enthalpy and hydration enthalpy.

Account for the following :

Acidic character increases from HF to HI.

F₂ has lower bond dissociation enthalpy than Cl₂. Why?