Applied Chemistry Multiple Choice Questions on “Cloud Point and Pour Point”.
1. The temperature expressed in multiples of 1oC at which the haze of the wax crystal appears when the oil is cooled under prescribed conditions is called ________
a) Pour point
b) Cloud point
c) Oxidation stability
d) Acid number
Answer: b
Clarification: The temperature expressed in multiples of 1oC at which the haze of the wax crystal appears when the oil is cooled under prescribed conditions is called cloud point. The haze of wax crystals is also called as cloud. It appears on the walls of the jar.
2. The cloud point is the index of the ___________ temperature.
a) Lowest
b) Highest
c) Reference
d) Infinity
Answer: a
Clarification: The cloud point is the index of the lowest temperature of its utility for certain applications. Every lubricating oil has cloud point in most of cases it is true.
3. The cloud point is used as ______ control parameter.
a) Quantity
b) Temperature
c) Speed
d) Quality
Answer: d
Clarification: The cloud point is used as the quality control parameter in chemical, petrochemical, personal care and other industries. Mainly it is measured in the oils.
4. Olive oil starts to solidify at __________
a) 1oC
b) 2oC
c) 3oC
d) 4oC
Answer: d
Clarification: Olive oil starts to solidify at 4oC. In winters or at very low temperatures around 0oC, then the olive oil begins to develop white waxy clumps of solidified oil that sink to the bottom of the container.
5. The lowest temperature expressed in multiple of 2oC at which the oil is observed to flow after cooled at prescribed conditions is called pour point.
a) True
b) False
Answer: b
Clarification: The lowest temperature expressed in multiple of 3oC at which the oil is observed to flow after cooled at prescribed conditions is called pour point. In cloud point, the oil hazes into crystal but in pour point it flows.
6. Pour point indicates the _______ of lubricating oil.
a) Dissolved wax concentration
b) Total wax concentration
c) Initial wax concentration
d) Weight of the wax
Answer: a
Clarification: Pour point indicates the dissolved wax concentration of lubricating oil. In pour point experiment two thermometers are present to measure the temperature off cooling mixture and lubricating oil.
7. In pour point experiment, the diameter of the cylindrical tube is of the diameter ____________
a) 3-3.35mm
b) 3-3.35cm
c) 3-3.35km
d) 3-35nm
Answer: b
Clarification: In pour point experiment, the diameter of the cylindrical tube is of the diameter is 3-3.35cm. The height of the cylinder is about 11.5-12.5cm. There is mark up to which the sample must be taken.
8. Cooling bath contains suitable ________
a) Ice
b) Water
c) Cooling mixture
d) Cool water
Answer: c
Clarification: Cooling bath contains suitable cooling mixture. It may be water sometimes but it is selected according to the lubricant. It is mainly used for cooling purposes.
9. The jacket is provided with a gasket that prevents the test jar from __________
a) Cooling
b) Heating
c) Breakage
d) Touching the jacket
Answer: d
Clarification: The jacket is provided with a gasket that prevents the test jar from touching the jacket. The jacket is fitted with a disk. The jacket is of 11.5cm depth.
10. The cloudiness of the lubricant is observed for every ___________
a) 1oC
b) 2oC
c) 3oC
d) 4oC
Answer: a
Clarification: The cloudiness of the lubricant is observed for every 1oC. First the oil is taken into the jar up to the marked level. The cork is fitted and then heated and observed for cloudiness for every 1oC raise in temperature.