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

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

Answer the following question.
Write the products obtained after the hydrolysis of lactose.

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?

The value of Δ_tG^θ for formation of Cr₂O₃ is −540 kJ mol⁻¹ and that of Al₂O₃ is −827 kJ mol⁻¹. Is the reduction of Cr₂O₃ possible with Al?

Predict conditions under which Al might be expected to reduce MgO.

Write the names of monomers of the following polymers.

Write the names of monomers of the following polymers:

Write the names of monomer of the following polymer:

How can you differentiate between addition and condensation polymerisation?