This set of Applied Chemistry Multiple Choice Questions & Answers (MCQs) focuses on “Sol-Gel Method and Chemical Reduction Method”.
1. Sol-gel method is ________ approach.
a) Bottom up
b) Up bottom
c) Top down
d) Down top
View Answer
Explanation: Sol-gel method is the bottom up approach for synthesis of nano materials. This process is mainly used to synthesize the nano materials.
2. Sol-gel method is known since ____________
a) 1970
b) 1960
c) 1980
d) 1990
View Answer
Explanation: Sol-gel method is known since 1980s. The technic is rediscovered in early 1970s when the glasses were produced without high temperature melting processes.
3. The sol-gel is a __________ of solid particle.
a) Sublimation
b) Melting
c) Colloidal suspension
d) Cool down
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Explanation: The sol-gel process is a colloidal suspension of the solid particles. It is also called as the molecular suspension of solid particles of ions in a solvent.
4. The gel is a ___________ mass.
a) Heavy molecular
b) Semi regid
c) Regid
d) Light molecular
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Explanation: The gel is a semi regid mass. It is formed when the solvent form sol begins to evaporate and particles or ions left behind being to join together in a continuous network.
5. Sol-gel method is ________ chemical process.
a) Dry
b) Wet
c) Semi liquid
d) Semi solid
View Answer
Explanation: Sol-gel method is the wet chemical process. It uses a sol to produce an integrated network that is called as formation of gel.
6. __________ undergo hydrolysis and poly condensation reactions.
a) Metal ions
b) Metal carbonates
c) Metal nitrates
d) Metal oxides
View Answer
Explanation: Metal oxides or metal chlorides undergo hydrolysis and poly condensation reactions to form a collide which is a system composed of nano particles dispersed in a solvent.
7. The solvent evolves towards the formation of an inorganic continuous network containing a ___________
a) Gaseous phase
b) Gel
c) Solid phase
d) Semi solid phase
View Answer
Explanation: The solvent evolves towards the formation of an inorganic continuous network containing a gel. It also may be in liquid phase.
8. Formation of an inorganic continuous network containing the metal centres with _________
a) Azo
b) Oxo
c) Nitro
d) Hydro
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Explanation: Formation of an inorganic continuous network containing the metal centres with Oxo(M-O-M) or else it can be hydroxo(M-OH-M).
9. After drying process the liquid phase is removed from the gel and ___________ is performed.
a) Calcination
b) De-oxygenation
c) Oxygenation
d) Hydrogenation
View Answer
Explanation: After drying process the liquid phase is removed from the gel and calcination is performed in order to enhance the mechanical properties. Alcohol is used as a solvent.
10. One of the advantages of sol-gel method is able to get uniform and _________ powder.
a) Micro size
b) Large size
c) Nano size
d) Small size
View Answer
Explanation: One of the advantages of sol-gel method is able to get uniform and small size powder. Another advantage of sol-gel method is to get new micro structure and composition at low temperature.
11. Sol-gel method can produce __________ systems.
a) Uniform multi component
b) Non uniform multi component
c) Multi component
d) Non uniform multi component
View Answer
Explanation: Sol-gel method can produce uniform multi component systems. Better control over the reactions is one of the advantages of sol-gel method.
12. Metal nano particles particularly _____________ nano particles are prepared by the chemical reduction method.
a) Silver
b) Gold
c) Platinum
d) Tungsten
View Answer
Explanation: Metal nano particles particularly silver nano particles are prepared by the chemical reduction method. This method is also belongs to bottom up approach.
13. The ___________ and citrate solution are used as reducing agents in chemical reduction method.
a) Hydrazine hydrate
b) Hydrazine
c) Hydrazone
d) Semi carbazene
View Answer
Explanation: The hydrazine hydrate and citrate solution are used as reducing agents in chemical reduction method. The hydrazine hydrate is of 2-12ppm and citrate solution of 1ppm is used.
14. To remove the excess silver ions the solution is washed with _________ under nitrogen stream.
a) Heavy water
b) Mineral water
c) Deioniser water
d) Impure water
View Answer
Explanation: To remove the excess silver ions the solution is washed with deioniser water under nitrogen stream. This process must be done three times.
15. The transparent colourless solution solution is changed into pale yellow from ___________ in chemical reduction method.
a) pale blue
b) Purple
c) Pale red
d) Dark brown
View Answer
Explanation: The transparent colourless solution is changed into pale yellow from pale red in the chemical reduction method. Later the dried powder of nano powder of nano silver is obtained by freeze drying.
Sanfoundry Global Education & Learning Series – Applied Chemistry.
To practice all areas of Applied Chemistry, here is complete set of 1000+ Multiple Choice Questions and Answers.
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