All Free Chemistry MCQs with Answers

• A. elevation in boiling point
• B. depression in freezing point
• C. osmotic pressure
• D. relative lowering of vapour pressure

Explanation: For determining the molar mass of a polymer osmotic pressure is preferred because it is done at normal (room) temperature.

• A. the Brownian motion become fast
• B. the Brownian motion becomes slow
• C. Brownian motion remains same
• D. none of these

Explanation: Brownian movement is due to the unequal bombardments of the moving molecules of dispersion medium on colloidal particles.

• A. As2S3 , Au in their colloidal sols are negatively charged
• B. Fe(OH)3 , Al(OH)3 are positively charged in their colloidal sols.
• C. Ag & Pt are positively charged in their colloidal sols.
• D. smoke is dispersion of positively charged colloidal particles of carbon in air

Explanation: Ag & Pt are negatively charged. They move towards anode in electrophoresis.

• A. oil in water
• B. water in oil
• C. both type
• D. none

Explanation: Emulsification takes place by reduction of interfacial tension between two phases.

• A. 50
• B. 5
• C. 47.6
• D. None of these

Explanation: Millimoles of NaCl added = 5 Volume of the sol containing NaCl solution = 100 mL.

• A. Catalyst
• B. Inhibitor
• C. Promotor
• D. Poison

Explanation: Poison, which come from the reacting substances or products of the reaction itself, accumulate on the surface of solid catalysts and cause…

• A. The curve showing the effect of temperature on the extent of adsorption at a given pressure
• B. The curve showing the variation of pressure with temperature, for a given amount of adsorption.
• C. The curve showing the variation of adsorption with pressure at a constant temperature.
• D. A line parallel to x-axis.

Explanation: The adsorption isostere is relation of the equilibrium pressure to the temperature at a constant value of the amount, or excess amount, of…

• A. Cataphoresis
• B. Electrosmosis
• C. Sedimentation
• D. Electrodialysis

Explanation: If the experiment is set such that only the colloidal particles are allowed to move and not the dispersion media particles it is known as…

• A. Will Decrease
• B. will Increase
• C. Remain same
• D. cannot say

Explanation: Physisorption is exothermic in nature. Therefore, After increasing temperature, the rate of physiosorption will derease.

• A. Option A
• B. Option B
• C. Option C
• D. Option D

Explanation: Colloidal solution of Sulpher is formed.

• A. Colloid becomes extremely stable
• B. Colloids get coagulated
• C. No effect is observed
• D. Colloids convert into true solution

Explanation: If all ions are removed the colloidal particles get neutrelized and associate with each other forming suspensions.

• A. Temperature fluctuation within the liquid phase.
• B. Attraction and repulsion between charges on the colloidal particles.
• C. Impact of the molecules of the dispersion medium on the colloidal particles.
• D. Convectional currents.

Explanation: Brownian motion is the random movement of the low weight particles suspended in a fluid.

• A. electrostatic potential
• B. sedimentation potential
• C. zeta potential
• D. chemical potential

Explanation: The potential differences existing between the surfaces of a solid particle immersed in a conducting liquid (e.g.

• A. the amount of gold present in the colloid.
• B. the amount of gold required to break the colloid.
• C. the amount of gold required to protect the colloid.
• D. none of the above.

Explanation: Gold number is 'least quantity of protective colloid in milligrams, which is just sufficient to prevent the coagulation of 10 ml of…

• A. Peptization
• B. Dialysis
• C. Protection
• D. Dissolution

Explanation: Peptization is the process responsible for the formation of stable dispersion of colloidal particles in dispersion medium.

• A. Positive charge
• B. Negative charge
• C. Sometimes positive and sometimes negative charge
• D. No charge

Explanation: The sol particle will carry positive charge.

• A. The viscosity of the medium
• B. The surface tension of the medium
• C. Both (A) and (B)
• D. The formation of an eletrical layer between the two phases

Explanation: Due to preferential adsorption of similar ions, an electrical double layer formed on the surface of colloidal particles. e.g.

• A. to improve the flavour
• B. to cause the mixture to solidify
• C. to stabilize the colloid and prevent crystal growth
• D. to prevent the formation of a colloid

Explanation: This is due to stabilize the colloid and prevent crystal growth.

• A. 0.025
• B. 0.25
• C. 2.5
• D. 250

Explanation: Gold number is 'least quantity of protective colloid in milligrams, which is just sufficient to prevent the coagulation of 10 ml of…

• A. It increases the equilibrium concentration of the products
• B. It is a substance which change the equilibrium constant of the reacting ion.
• C. It shortens the time to reach equilibrium.
• D. It supplies energy to the reaction.

Explanation: A catalyst is substance that increases rate of reaction and it shortens the to reach equilibrium.