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

Aldehydes and ketones react with hydroxylamine to form ______.

The slope in the plot of `log  ["R"]_0/(["R"])` Vs. time for a first-order reaction is ______.

When D-glucose reacts with HI, it forms ______.

Solubility of gas in liquid decreases with increase in ______.

Which of the following molecules has a chiral centre correctly labelled with an asterisk (*)?

Assertion (A): Trans [CrCl₂(ox)₂]³⁻ shows optical isomerism.

Reason (R): Optical isomerism is common in octahedral complexes involving didentate ligands.

Give the reaction of glucose with hydrogen cyanide. Presence of which group is confirmed by this reaction?

Give a reason for the following observations:

Penta-acetate of glucose does not react with hydroxylamine.

In which of the following solvents, the \[\ce{C4H8NH3+X–}\] is soluble?

Radioactive decay follows first-order kinetics. The initial amount of two radioactive elements X and Y is 1 gm each. What will be the ratio of X and Y after two days if their half-lives are 12 hours and 16 hours respectively?

Out of p-tolualdehyde and p-nitrobenzaldehyde, which one is more reactive towards nucleophilic addition reactions, why?

Write the structure of the product formed when acetone reacts with 2, 4 DNP reagent.

Arrange the decreasing boiling point.

\[\ce{CH3COOH, C2H5OH, CH3NH2, CH3OCH3}\]

Write the two applications of Henry’s law.

Amongst the following compounds, identify which are insoluble, partially soluble and highly soluble in water?

1. phenol
2. toluene
3. formic acid
4. ethylene glycol
5. chloroform
6. pentanol

Give an example of the reaction in the following case.

Oxime

Give an example of the reaction in the following case.

Imine

Sucrose decomposes in acid solution to give glucose and fructose according to the first order rate law. The half life of the reaction is 3 hours. Calculate fraction of sucrose which will remain after 8 hours.

Arrange the following in increasing order of their basic strength in aqueous solution:

\[\ce{CH3NH2, (CH3)3N, (CH3)2NH}\]

For a first order reaction, show that time required for 99% completion is twice the time required for the completion of 90% of reaction.