Engineering Chemistry Multiple Choice Questions on “Alkalinity of Water and its Estimation”.
1. Which source of water is free from hardness and surface impurities?
a) Surface water
b) Underground water
c) Rain water
d) Sea water
Answer: c
Clarification: Rain water is free from hardness and surface impurities. Surface water and sea water is very impure and saline.
2. Water from reservoirs comes under the category of ____________
a) Surface water
b) Rain water
c) Underground water
d) Sea water
Answer: a
Clarification: Water from reservoirs comes under the category of surface water. Reservoirs are the large storage tanks which are used for storing and distributing water to the channels.
3. Which of the following indicator is pink in basic medium?
a) Methyl orange
b) Phenolphthalein
c) Starch
d) Litmus paper
Answer: b
Clarification: Phenolphthalein indicator is pink in basic medium, methyl orange is orange, starch is colorless and litmus paper shows different colors in different mediums.
4. The temporary hardness in water is due to ____________
a) OH–
b) CO32-
c) H+
d) HCO3–
Answer: d
Clarification: The temporary hardness in water is due to HCO3–. It can easily be removed by mere action of boiling.
5. With respect to the constituents causing alkalinity in water, which of the following situation never arises?
a) CO32- and HCO3– together
b) HCO3– and OH– together
c) OH– only
d) OH– and CO32- together
Answer: b
Clarification: HCO3– and OH– together combines to form CO32- ions. Therefore, this situation never arises.
6. What is the disadvantage of using high alkaline water?
a) It may lead to infections
b) It may lead to electrolysis
c) It may lead to caustic embrittlement
d) It may lead to indigestion
Answer: c
Clarification: High alkaline water leads to caustic embrittlement and deposition of precipitates and sludges in boiler tubes and pipes.
7. The alkalinity due to hydroxide ion when P > M/2 will be ____________
a) M-2P
b) 2(M-P)
c) Nil
d) 2P-M
Answer: d
Clarification: The alkalinity due to hydroxide ion when P > M/2 will be (2P-M).
8. The alkalinity due to bicarbonate ion when P < M/2 will be ____________
a) M-2P
b) 2(M-P)
c) Nil
d) 2P-M
Answer: a
Clarification: The alkalinity due to bicarbonate ion when P < M/2 will be (M-2P).
9. The alkalinity due to carbonate ion is 2P when?
a) P = M
b) P > M/2
c) P = M/2
d) P < M/2
Answer: c
Clarification: The alkalinity due to carbonate ion is 2P when P = M/2.
10. Alkalinity is a measure of the ability of water to neutralize the acids.
a) True
b) False
Answer: a
Clarification: Alkalinity is a measure of the ability of water to neutralize the acids. Measuring alkalinity is important in determining a stream’s ability to neutralize acidic pollution from rainfall or waste water.