Science (English Medium) कक्षा १२ - CBSE Question Bank Solutions

Calculate the mass of a compound (molar mass = 256 g mol⁻¹) to be dissolved in 75 g of benzene to lower its freezing point by 0.48 K (K_f = 5.12 K kg mol⁻¹).

Write an important characteristic of lyophilic sols.

How do you prepare:

Na₂Cr₂O₇ from Na₂CrO₄?

 Write one example of a Natural polymer.

 Write one example of a thermosetting polymer.

Define the following term:
Denaturation of protein

Give reasons for the following:

Sulphur in vapour state shows paramagnetic behaviour.

Yellow colour of NaCl crystals in sodium vapour is due to ____________.

The following diagram shows:

Which of the following is a colligative property?

Two solutions have different osmotic pressures. The solution of higher osmotic pressure is called ____________.

At constant temperature the osmotic pressure of a solution is ____________.

20 g of a substance were dissolved in 500 mL of water and the osmotic pressure of the solution was found to be 600 mm of mercury at 15°C. The molecular weight of the substance is:

The average osmotic pressure of human blood is 7.8 bar at 37°C. What is the concentration of an aqueous NaCl solution that could be used in the blood stream?

Osmotic pressure of a solution is 0.0821 atm at a temperature of 300 K. The concentration in moles/litre will be:

Which of the following will have metal deficiency defect?

A solution containing 10 g per dm³ of urea (molar mass 60 g mol⁻¹) is isotonic with 5% solution of non-volatile solute, M_B of solute is:

The temperature at which 10% aqueous solution of (W/V) of glucose will show the osmotic pressure of 16.4 atoms is: (R = 0.082 L atom K⁻¹ mol⁻¹)

Assertion: Both rhombic and monoclinic sulphur exist as S₈ but oxygen exists as O₂.

Reason: Oxygen forms pπ – pπ multiple bonds due to small size and small bond length but pπ – pπ bonding is not possible in sulphur.

Which of the following is a non-stoichiometric defect?