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WorksheetsColloid & Surface Chemistry Quiz
Total questions: 10
Worksheet time: 10mins
A colloidal system having a solid substance as the dispersed phase and a liquid as the dispersion medium.
Identify the colloidal type that best describes the system above.
Gel
Emulsion
Solid Sol
Sol
Select the FALSE statement about adsorption.
The value of adsorption enthalpy of physical adsorption is less than chemical adsorption.
Physical adsorption occurs due to Van der Waals'forces.
Chemical adsorption decreases at high temperature and low pressure.
Physical adsorption is reversible.
Identify the property of colloid related to Tyndall effect.
Mechanical property
Colligative property
Optical property
Electrical property
Foam is a colloidal system which consists of a dispersed phase and a dispersion medium. Indicate the dispersed phase and dispersion medium of foam, respectively.
Liquid and liquid
Solid and gas
Liquid and solid
Gas and liquid
Recognize the method in preparing lyophilic sol.
Chemical reduction
Peptization
Mechanical dispersion
Direct mixing of the solid with the liquid
Select the CORRECT statement regarding adsorption process.
A substance is encapsulated in the solid or liquid form.
A substance is distributed throughout the solid or liquid form.
A substance becomes attached to the surface of a solid or a liquid.
It may involve chemisorption only.
" A substance is first ground to coarse particles and then mixed with the dispersion medium to produce a suspension."
Name the method to produce sol as mentioned above.
Double decomposition
Mechanical dispersion
Bredig's arc
Peptization
Select the CORRECT property of a lyophobic sol.
The colloidal particles are not easily detected by the ultra microscope.
The surface tension of dispersed phase is generally lower than that of the dispersion medium.
The viscosity of a sol is similar to that of the dispersion medium (solvent).
Addition of low concentration of electrolytes has little effect on the coagulation.
Define adsorbate.
The removal of adsorbed particles.
A solid material on which adsorption occurs.
A substance in the adsorbed phase.
The study on the interaction phenomena on the surface.
Choose the CORRECT assumptions of the Langmuir isotherm.
Answers can be more than one options.
The solid surface of adsorbent is uniform (all the adsorption sites are equivalent. Every side have same energy (homogeneous surface).
All adsorption occurs through same mechanism.
A maximum of a monolayer (one adsorbate molecule per site) can be adsorbed. Adsorption cannot proceed above monolayer coverage.
Adsorbed molecule do not interact; adsorption is localized (immobile)
Adsorption can proceed multilayer coverage.
