This set of Food Chemistry Multiple Choice Questions & Answers (MCQs) focuses on “Dispersed Systems – Gels”.
1. Gels behave like solids because of ___________
a) Two dimensional structure
b) Due to crystallization
c) Two dimensional cross link
d) Three dimensional cross link
View Answer
Explanation: Gel is a semi-solid jelly like systems. Gels behave like solids because of three-dimensional cross-linked network within the liquid. It is the crosslinking within the fluid that gives a gel its structure and contributes to the adhesive stick.
2. Gels are what type of dispersions?
a) Liquid in solid
b) Gas in liquid
c) Solid in liquid
d) Solid in gas
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Explanation: Gels are a dispersion of molecules of a liquid within a solid in which liquid particles are dispersed in the solid medium.
3. Who coined the name gel?
a) Alexander flemming
b) Thomas graham
c) Eddison
d) Peter dhuranth
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Explanation: The word gel was coined by 19th-century Scottish chemist Thomas Graham by clipping from gelatin. A gel is a solid jelly-like material that can have properties ranging from soft and weak to hard and tough.
4. Which gel posses’ similarity to natural tissues?
a) Hydrogels
b) Organogels
c) Xerogels
d) Polyionic polymers
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Explanation: Hydrogels are highly absorbent (they can contain over 90% water) natural or synthetic polymeric networks. Because of their considerable water content, they are very flexible.
5. Which gel is also known as ‘Smart Gels’ or ‘Intelligent Gels’?
a) Hydrogels
b) Organogels
c) Xerogels
d) Polyionic polymers
View Answer
Explanation: Hydrogels are sensitive to environment. They can sense changes of pH, ionic concentration, temperature and release their load as result of such a change. So, called as ‘Smart gels’ or ‘Intelligent gels’.
6. Which one is a non-crystalline, non-glassy thermoreversible (thermoplastic) solid material?
a) Hydrogels
b) Organogels
c) Xerogels
d) Polyionic polymers
View Answer
Explanation: An organogel is a semi-solid, non-crystalline, non-glassy thermoreversible (thermoplastic) solid material.
7. Which type of gel has high porosity (15–50%) and enormous surface area (150–900 m2/g)?
a) Hydrogels
b) Organogels
c) Xerogels
d) Polyionic polymers
View Answer
Explanation: A xerogel is a solid formed from a gel by drying with unhindered shrinkage. Xerogels usually retain high porosity (15–50%) and enormous surface area (150–900 m2/g), along with very small pore size (1–10 nm).
8. Aerogel is ____________
a) Low density
b) High density
c) Less viscous
d) High viscous
View Answer
Explanation: When solvent removal occurs under supercritical conditions, the network does not shrink and a highly porous, low-density material known as an aerogel is produced.
9. Hybrid hydrogels are also known as ________
a) Hydrogels
b) Organogels
c) Xerogels
d) Nanocomposite hydrogels
View Answer
Explanation: Nanocomposite hydrogels are also known as hybrid hydrogels, can be defined as highly hydrated polymeric networks, either physically or covalently crosslinked with each other and/or with nanoparticles or nanostructures.
10. The tendency of becoming fluid when agitated is called as ________
a) Aerogels
b) Thixotrophy
c) Crystalisation
d) Hydrogels
View Answer
Explanation: Many gels display thixotropy – they become fluid when agitated, but resolidify when resting.
Sanfoundry Global Education & Learning Series – Food Chemistry.
To practice all areas of Food Chemistry, here is complete set of Multiple Choice Questions and Answers.
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