PUC Science 2nd PUC Class 12 - Karnataka Board PUC Question Bank Solutions for Chemistry

Write the structure of the major product in each of the following reaction :

Give a simple chemical test to distinguish between the following pair of compounds :

CH₃CH₂CHO and CH₃CH₂COCH₃

How will you distinguish between the following pair of terms?

Tetrahedral and octahedral voids

What type of deviation is shown by a mixture of ethanol and acetone? Give reason.

Propanal and Propanone

Out of CH₃CH₂ – CO – CH₂ – CH₃ and CH₃CH₂ – CH₂ – CO – CH₃, which gives iodoform test?

What do you understand by the term glycosidic linkage?

Which of the following is a fibre? Nylon, neoprene, PVC

Write the structures of A, B and C in the following:

If the radius of the octahedral void is r and the radius of the atoms in close packing is R, derive the relation between r and R.

The vapour pressures of pure liquids A and B are 450 and 700 mm Hg respectively, at 350 K. Find out the composition of the liquid mixture if the total vapour pressure is 600 mm Hg. Also, find the composition of the vapour phase.

Vapour pressure of pure water at 298 K is 23.8 mm Hg. 50 g of urea (NH₂CONH₂) is dissolved in 850 g of water. Calculate the vapour pressure of water for this solution and its relative lowering.

An aqueous solution of 2% non-volatile solute exerts a pressure of 1.004 bar at the normal boiling point of the solvent. What is the molar mass of the solute?

The vapour pressure of water is 12.3 kPa at 300 K. Calculate vapour pressure of 1 molal solution of a non-volatile solute in it.

Calculate the mass of a non-volatile solute (molar mass 40 g mol⁻¹) which should be dissolved in 114 g octane to reduce its vapour pressure to 80%.

A solution containing 30 g of non-volatile solute exactly in 90 g of water has a vapour pressure of 2.8 kPa at 298 K. Further, 18 g of water is then added to the solution and the new vapour pressure becomes 2.9 kPa at 298 K. Calculate:

1. molar mass of the solute.
2. vapour pressure of water at 298 K.

100 g of liquid A (molar mass 140 g mol⁻¹) was dissolved in 1000 g of liquid B (molar mass 180 g mol⁻¹). The vapour pressure of pure liquid B was found to be 500 torr. Calculate the vapour pressure of pure liquid A and its vapour pressure in the solution if the total vapour pressure of the solution is 475 Torr.

Benzene and toluene form ideal solution over the entire range of composition. The vapour pressure of pure benzene and toluene at 300 K are 50.71 mm Hg and 32.06 mm Hg respectively. Calculate the mole fraction of benzene in vapour phase if 80 g of benzene is mixed with 100 g of toluene.

What do you mean by activity and selectivity of catalysts?

Why is zinc not extracted from zinc oxide through reduction using CO?