Sunday 15 December 2013

CY6151 Engineering Chemistry - I - 2 Marks with Answers - 2013 Edition



Anna University,Chennai

First Semester

Department of Chemistry

(Regulation 2013)

Semester : 01
Department : Common to ALL Departments
Year : I year
Regulation : 2013
Subject Code : CY6151
Subject Name : Engineering Chemistry - I
Content : CY6151 Engineering Chemistry - I - Part A - 2 Marks with Answers 


SRINIVASAN ENGINEERING COLLEGE, PERAMBALUR-621212
DEPARTMENT OF SCIENCE AND HUMANITIES
CY21 51- ENGINEERING CHEMISTRY-I
QUESTION BANK
PART-A

UNIT-I

POLYMER CHEMISTRY

1. What is degree of polymerization?
No. of repeating units in a polymeric network.

2. Mention functionality of a monomer with suitable example.
No. of bonding or reactive site in a monomer.

3. What are co- polymers? Give example.
Formed by joining of two different monomer.

4. What are engineering plastics?
High molecular weight polymer resin posses mechanical strength toughness 
durability.

5. What is a dead polymer?
The product of additional polymerization is known as dead polymer's

6. Define Tacticity.
The orientation of monomeric units in a polymer is called tacticity.

7. Write any two thermal initiators used in thermal polymerization.
Acetyl peroxide & Benzoyl peroxide.

8. Mention the monomers which are polymerized in anionic polymerisation.
Acrylonitrite, methylacrylate, methylmethacrylate.

9. What are homochain and heterochain polymer?
Homochain: Addition polymer, Chain is made up of same type of atom
Heterochain: condensation polymer, Chain is made up of different types of atom

10. Why thermosetting plastics cannot be remolded?
 Because the chains are joined by strong covalent force

UNIT-II

CHEMICAL THERMODYNAMICS

1. What is a system?
It is the part if the physical universe to which we direct out attention for the 
purpose of experimental or theoretical investigation.

2. What is an extensive property?
An extensive property of a system depends upon the total amount of substance in the system.

3. What is a process? Mention its type.
The operation which brings about the changes in the state of the system is called a process. Types: i) Isothermal Process ii) Adiabatic process iii) cyclic process.

4. Define II law of thermodynamics?
Heat cannot of itself pass from colder to hotter body without the intervention of any external agency.

5. What is Gibbs free energy?
The isothermally available energy present in a system is called free energy.

6. Mention any two applications of clausius.
      Molar Latent heat of vaporization can be calculated.
      To study the effect of pressure on boiling point.

7. Define work function?
The part of the internal energy which is isothermally available is called the work function of the system.

8. Define entropy.
It is the measure of degree of disorder or randomness in a molecular system.

9. What is an adiabatic process?
A process is said to be adiabatic if no heat enters or leaves the system during any step of the process.

10. Write the significance of vant’ hoff equation
 To calculate pH of a reaction by measuring the values of equilibrium constant  at two different temperatures.
 To calculate the value of equilibrium constant at a particular temperatures.

UNIT –III
PHOTOCHEMISTRY & SPECTROSCOPY

1. State Grothus –Draper Law.
Only the light that is absorbed by the substance can bring about a chemical change in the substance.

2. State Starck- Einstein Law.
Each molecule taking part in a photochemical reaction absorbs one quantum of radiation.

3. Write any two reasons for high quantum yield.
  Formation of intermediate product will act as a catalyst.
  Absobtion of raditions in the primary step produces atoms or free radicals which initiate a series of chain reaction.

4. What is a photosensitiser?
The foreign substance which absorbs light radiation and transfers the absorbed energy to the reactant is called photo sensitizer.

5. What is quenching?
When the foreign substance in the excited state colloids with another substance it gets converted into some other product is called quenching.

6. What are chromophores? Give example.
The group (multiple bonds) which are the reason for colour of a compound.
-N=N-(azo).

7. Define the term bathochromic shift.
The shift of an absorbtion maximum towards longer wavelength is called
 bathochromic or red shift.

8. What if finger print region?
The IR region 1400-700cm-1 gives very rich and intense absorption bands is called finger print region.

9. Methane does not absorb IR energy. Why?
Because four hydrogen atoms of methane vibrate symmetrically.

10. What are the functions of auxochromes?
It deepens the color of the chromophore.
They are required to make the chromogen -a dye.

UNIT-V
NANOCHEMISTRY

1. Define Nanotechnology.
It is defined as the design, production, characterization and applications of
systems, structures and devices of nanometer size.

2. How are nanomaterial classified?
Nanomaterials with one dimension, Nanomaterials with two dimension,
nanomaterials with three dimension.

3. What are nanoparticles?
These are particles having three dimensional nanoscale. Eg. CaO, CdS.

4. What is a top down process?
Bulk materials are broken into nanosized particles in this method

5. What is a bottom up process?
Nanosized materials are produced by building up of atom by atom in this process.

6. What are nanotubes?
Nanotube has a nanometer scale tube like structure.

7. What are nanorods?
Nanomaterials having long sticks or rod shapes with diameter in nanoscale and a length very much longer are called nanorods.

8. Mention any three uses of nanorods.
 In display technologies.
 In Energy harvesting.
 In LED

9. Mention any four methods used to synthesis nanomaterial.
 Precipitation
 Hydrothermal
 Solvothermal
 Thermolysis

10. Mention the various fields in which nanomaterials are used?
 Electrical and Electronic Devices.
 Memory Devices.
 Fuel Cells.
 Energy production




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