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

Sugar is the main source of energy as it produces energy on metabolic decomposition. But these days low calorie drinks are more popular, why?

Pickles have a long shelf life and do not get spoiled for months, why?

What is the difference between saccharin and saccharic acid?

Name an artificial sweetener which is derivative of sucrose.

Name two α-amino acids which form a dipeptide which is 100 times more sweet than cane sugar?

Aspartame is unstable at cooking temperature, where would you suggest aspartame to be used for sweetening?

Sodium salts of some acids are very useful as food preservatives. Suggest a few such acids.

Assertion: All chemicals added to food items are called food preservatives.

Reason: All these chemicals increase the nutritive value of the food.

Assertion: Preservative are added to food items.

Reason: Preservatives inhibit the growth of microorganisms.

Assertion: Artificial sweeteners are added to the food to control the intake of calories.

Reason: Most of the artificial sweeteners are inert and do not metabolise in the body.

\[\ce{H2}\] gas is adsorbed on activated charcoal to a very little extent in comparison to easily liquefiable gases due to:

(i) very strong van der Waal’s interaction.

(ii) very weak van der Waals forces.

(iii) very low critical temperature.

(iv) very high critical temperature.

Give reasons to support the answer:

Presence of Alpha hydrogen in aldehydes and ketones is essential for aldol condensation.

In a coordination entity, the electronic configuration of the central metal ion is t_2g³ e_g¹

Is the coordination compound a high spin or low spin complex?

What happens when reaction:

Aniline reacts with chloroform in the presence of alcoholic potassium hydroxide

Cross aldol condensation occurs between

What is the no. of possible isomers for the octahedral complex [Co(NH₃)₂(C₂O₄)₂]?

Explain how and why will the rate of reaction for a given reaction be affected when a catalyst is added.

Using Valence bond theory, explain the following in relation to the paramagnetic complex [Mn(CN)₆]³⁻ 

1. type of hybridization
2. magnetic moment value
3. type of complex – inner, outer orbital complex

Identify the major product formed when 2-cyclohexylchloroethane undergoes a dehydrohalogenation reaction. Name the reagent which is used to carry out the reaction.

Arrange the following in the increasing order of their property indicated:

4-Nitrobenzoic acid, benzoic acid, 3,4-Dinitrobenzoic acid, 4-Methoxy benzoic acid (Acid strength)