Engineering Chemistry Questions and Answers – Boiler Feed Water

This set of Engineering Chemistry Multiple Choice Questions & Answers (MCQs) focuses on “Boiler Feed Water”.

1. Water is mainly used in boilers for the generation of ________________
a) Power
b) Electricity
c) Steam
d) Current
View Answer

Answer: c
Explanation: Water is mainly used in boilers for the generation of steam. This steam is further used in the power plants for the generation of electricity.

2. Which of the following should not be a composition of boiler-feed water?
a) Hardness should be below 0.2ppm
b) Its caustic alkalinity should lie between 0.15 to 0.45 ppm
c) Its soda alkalinity should be 0.45-1 ppm
d) Its caustic alkalinity should be 1.5-2 ppm
View Answer

Answer: d
Explanation: Its caustic alkalinity should be 0.15-0.45 ppm. All the other options are correct. Hardness should be below 0.2ppm, caustic alkalinity should lie between 0.15 to 0.45 ppm and soda alkalinity should be 0.45-1 ppm.

3. Which of the following is not a result of the excess of impurity in boiler-feed?
a) Scale and sludge formation
b) Decomposition
c) Corrosion, priming and foaming
d) Caustic embrittlement
View Answer

Answer: b
Explanation: Excess of impurities in boiler-feed results in scale and sludge formation, corrosion, priming, foaming and caustic embrittlement. It does not contribute to the decomposition process.
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4. If the precipitate formed is soft, loose and slimy, these are __________ and if the precipitate is hard and adhering on the inner wall, it is called _____________
a) Sludges, scale
b) Scale, sludges
c) Sludges, rodent
d) Scale, rodent
View Answer

Answer: a
Explanation: If the precipitate formed is soft, loose and slimy, these are sludges and if the precipitate is hard and adhering on the inner wall, it is called scale. A rodent is a small furry mammal whose teeth never stop growing.

5. Which of the following option is incorrect about the sludges?
a) Sludges are soft, loose and slimy precipitate
b) They are non-adherent deposits and can be easily removed
c) Formed generally at heated portions of the boiler
d) Can be removed by blow down operation
View Answer

Answer: c
Explanation: Sludges are formed generally at colder portions of the boiler. All the other options are correct. Sludges are soft, loose and slimy precipitate, non-adherent deposits and can be easily removed by blow down operation.
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6. The scales decrease the efficiency of boiler and chances of explosions are also there.
a) True
b) False
View Answer

Answer: a
Explanation: The scales decrease the efficiency of boiler and chances of explosions are also there. Scale is the precipitate that is hard and adhering on the inner wall.

7. The propulsion of water into steam drum by extremely rapid, almost explosive boiling of water at the heating surface is called ___________
a) Foaming
b) Priming
c) Corrosion
d) Caustic embrittlement
View Answer

Answer: b
Explanation: The propulsion of water into steam drum by extremely rapid, almost explosive boiling of water at the heating surface is called priming. Priming is necessary as it removes all the air voids from the passage of water.
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8. The phenomenon during which the boiler material becomes brittle due to accumulation of caustic substances is known as ___________
a) Foaming
b) Priming
c) Corrosion
d) Caustic embrittlement
View Answer

Answer: d
Explanation: The phenomenon during which the boiler material becomes brittle due to accumulation of caustic substances is known as caustic embrittlement. This can be prevented by using sodium phosphate instead of sodium carbonate as softening reagents.

9. Foaming is caused by the formation of ___________
a) Acids
b) Alcohols
c) Oils and alkalis
d) Ketones
View Answer

Answer: c
Explanation: Foaming is caused by the formation of oils and alkalis. Oils and Alkalis becomes sticky and greasy on the surface and hence results in foaming.
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10. Corrosion is the decay or disintegration of boiler body material either due to chemical or electrochemical reaction with environment.
a) True
b) False
View Answer

Answer: a
Explanation: Corrosion is the decay or disintegration of boiler body material either due to chemical or electrochemical reaction with environment. It converts a refined metal to a more stable form, such as its oxide, hydroxide, or sulphide.

Sanfoundry Global Education & Learning Series – Engineering Chemistry.

To practice all areas of Engineering Chemistry, here is complete set of 1000+ Multiple Choice Questions and Answers.

If you find a mistake in question / option / answer, kindly take a screenshot and email to [email protected]

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Manish Bhojasia, a technology veteran with 20+ years @ Cisco & Wipro, is Founder and CTO at Sanfoundry. He lives in Bangalore, and focuses on development of Linux Kernel, SAN Technologies, Advanced C, Data Structures & Alogrithms. Stay connected with him at LinkedIn.

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