List of top Chemistry Questions asked in UP Board XII

How will you prepare the following? (Write only chemical equations.)

(i) Benzene from benzoic acid:

(ii) Phthalimide from phthalic acid:

(iii) \( m \)-Nitrobenzaldehyde from benzaldehyde:

When an organic compound of molecular formula \( C_4H_8O_2 \) undergoes hydrolysis with dilute \( H_2SO_4 \), a carboxylic acid A and an alcohol B are obtained. On oxidising B with chromic acid, carboxylic acid A is obtained. On heating A with \( P_2O_5 \), acid anhydride C of this acid is obtained. On hydrolysing this anhydride, acid A is obtained again. Identify A, B, and C and also write chemical equations related to them.

State the source and the diseases caused by the deficiency of the following vitamins: Vitamin A
Vitamin C
Vitamin D
Vitamin E
Vitamin K

Write a short note on amino acids and nucleic acids.

Write Valence Bond Theory (VBT) of coordination compounds. Also state the demerits of this theory.

State Raoult's law related to lowering of vapour pressure. Calculate the vapour pressure of pure water at 293 K temperature when 25 g of glucose is dissolved in 450 g of water. Vapour pressure of pure water at 293 K temperature is 1535 mmHg.

What are d-block and f-block elements?

What happens when (write only chemical equations):

(i) Ethanol is heated with sodium bromide and conc. \( H_2SO_4 \):

(ii) Toluene reacts with \( Cl_2 \) gas in the presence of Fe powder in the dark:

(iii) Benzene diazonium chloride reacts with water:

(iv) 2-Bromopentane is heated with alcoholic \( KOH \):

Why is bromine atom of bromoethane more reactive than that of bromobenzene? Write only chemical equation of the reaction of bromoethane with \( Na \) in presence of dry ether.

Explain the importance of coordination compounds.

Write different resonating structures of aniline.

For the reaction \( \frac{1}{2} A \rightarrow 2B \), rate of dissociation of \( A \) and rate of formation of \( B \) is related as follows:

What is the effect of catalyst on the rate of reaction? A first-order reaction is 40\% completed in 50 minutes. Calculate the time taken for 80\% completion of the reaction. (Given: \(\log 2 = 0.3010\) and \(\log 6 = 0.7782\))

Write a short note on denaturation of proteins.