6. What is corrosion? Which is the most important material used for metallic coating?
Ans:
Corrosion is a natural process,
which converts a refined metal to a more stable form, such as its oxide, hydroxide,
or sulfide. It is the gradual destruction of materials (usually metals) by
chemical reaction with their environment.
7.Explain the third law of thermodynamics.
Ans:
The third law states that 'As a
system approaches absolute zero, the entropy of the system approaches a minimum
value'.
8.What is entropy?
Ans:
Entropy is a measure of
disorderliness. It explains the system's closeness to equilibrium.
9.What is Gibbs free energy?
Ans:
It is the available energy or the
greatest amount of mechanical work done by a system at constant temperature and
pressure.
At what temperature does water
have maximum density?
At 4 deg C the density of water
is 1000 kg/cu.m.
10.Explain global warming?
Ans:
It is the average temperature
increase in the surface temperature of the earth, mainly due to increased
concentration of greenhouse gases. The greenhouse gases capture the heat
radiated by the earth, inside the atmosphere, enabling the increase in
temperature.
What is carbon sequestration?
11.What are the greenhouse gases in earth's atmosphere?
Ans:
Water vapor, carbon dioxide,
ozone, methane, nitrous oxide and CFC.
12.Define octane number?
Ans:
It is the resistance to
detonation of a fuel in a spark ignition engine compared to the
isooctane-n-heptane mixture.
Explain the working of a spray
condenser
13.Define viscosity.
Ans:
Viscosity is a measure of a
fluid's resistance to shear stress.
14.Units of viscosity?
Ans:
SI units: kg/m.s
CGS units: g/cm.s or poise (P)
In most of the situations and in
literature viscosity will be expressed in poise
units.
1 poise (P) = 0.1 kg/m.s
15.How can we calculate heating of natural gas?
Ans:
We are using gas chromatogrpahy for calculating the carorific value of a
combution gas
<Back I Next>
EmoticonEmoticon