A miscible mixture of C₆H₆ + CHCl₃ can be separated by

• sublimation

• distillation

• filtration

• crystallisation

Electrophile that participates in nitration of benzene is

• NO⁺

• NO${}_2^{+}$

• NO

• NO${}_3^{-}$

23.

The half-life period of a first order reaction is 60 min. What percentage will be left over after 240 min?

• 6.25%

• 4.25%

• 5%

• 6%

Which of the following is not a colligative property?

• Osmotic pressure

• Optical activity

• Depression in freezing point

• Elevation in boiling point

The contribution of particle at the edge centre to a particular unit cell is

• $\frac{1}{2}$

• $\frac{1}{4}$

• 1

• $\frac{1}{8}$

When an electrolyte is dissociated in solution, the van't Hoff factor (i) is

• > 1

• < 1

• = 0

• = 1

Which of the following is incorrect in a galvanic cell?

• Oxidation occurs at anode

• Reduction occurs at cathode

• The electrode at which electrons are gained is called cathode

• The electrode at which electrons are lost is called cathode

A secondary cell is one

• can be recharged

• can be recharged by passing current through it in the same direction

• can be recharged by passing current through it in the opposite direction

• cannot be recharged

Osmotic pressure of the solution can be increased by,

• increasing the temperature of the solution

• decreasing the temperature of the solution

• increasing the volume of the vessel

• diluting the solution

The amount of current in Faraday, is required for the reduction of 1 mole of Cr₂O${}_7^{2-}$ ions to Cr³⁺ is

• 1 F

• 2 F

• 6 F

• 4 F