Science (English Medium) कक्षा १२ - CBSE Question Bank Solutions for Chemistry

Assertion: The boiling points of alkyl halides decrease in the order:

RI > RBr > RCl > RF

Reason: The boiling points of alkyl chlorides, bromides and iodides are considerably higher than that of the hydrocarbon of comparable molecular mass.

Arrange the following compounds in increasing order of boiling point. Propan-1-ol, butan-1-ol, butan-2-ol, pentan-1-ol

Explain why alcohols and ethers of comparable molecular mass have different boiling points?

Assertion: Boiling points of alcohols and ethers are high.

Reason: They can form intermolecular hydrogen-bonding.

Addition of water to alkynes occurs in acidic medium and in the presence of \[\ce{Hg^{2+}}\] ions as a catalyst. Which of the following products will be formed on addition of water to but-1-yne under these conditions.

Compound \[\begin{array}{cc}
\phantom{.....}\ce{O}\\
\phantom{.....}||\\
\ce{Ph - O - C - Ph}
\end{array}\] can be prepared by the reaction of ______.

The correct increasing order of basic strength for the following compounds is ______.

(I)

(II)

(III)

The most reactive amine towards dilute hydrochloric acid is:

The correct decreasing order of basic strength of the following species is ______.

\[\ce{H2O, NH3, OH-, NH^{-}2}\]

Explain why \[\ce{MeNH2}\] is stronger base than \[\ce{MeOH}\]?

In disaccharides, if the reducing groups of monosaccharides i.e. aldehydic or ketonic groups are bonded, these are non-reducing sugars. Which of the following disaccharide is a non-reducing sugar?

Match the following enzyms given in Column I with the reactions they catalyse given in Column II.

Which of the following statements is not true about low-density polythene?

Out of chain growth polymerisation and step growth polymerisation, in which type will you place the following.

What is the role of benzoyl peroxide in addition polymerisation of alkenes? Explain its mode of action with the help of an example.

Why should the monomers used in addition polymerisation through free radical pathway be very pure?

Match the polymer of column I with correct monomer of column II.

Match the polymers given in Column I with their chemical names given in Column II.

Match the polymers given in Column I with the preferred mode of polymerisation followed by their monomers.

Assertion: Olefinic monomers undergo addition polymerisation.

Reason: Polymerisation of vinyl chloride is initiated by peroxides/ persulphates.