This set of Engineering Chemistry Quiz focuses on “Calgon Conditioning”.
1. What is Calgon?
a) Potassium hexa meta sulphate
b) Magnesium hexa meta phosphate
c) Sodium hexa meta phosphate
d) Calcium hexa meta sulphate
View Answer
Explanation: Calgon is sodium hexa meta phosphate. Calgon prevents limescale build-up in washing machines all over the world to protect the heating element, pipes and drum of the machines.
2. Calgon is added to boiler water to prevent ___________
a) Foaming
b) Sludge and scale formation
c) Priming
d) Corrosion
View Answer
Explanation: Calgon is added to boiler water to prevent sludge and scale formation. Calgon prevents limescale build-up in washing machines all over the world to protect the heating element, pipes and drum of the machines.
3. Calgon converts the scale forming impurity like CaSO4 into ___________
a) Soluble complex compound
b) Insoluble complex compound
c) Soluble acids
d) Insoluble acids
View Answer
Explanation: Calgon converts the scale forming impurity like CaSO4 into soluble complex compound which are harmless to boiler.
4. The quantity of calgon to be added to prevent scale and sludge formation is ___________
a) 10-20 ppm
b) 30-50 ppm
c) 0.005-0.1 ppm
d) 0.5-5 ppm
View Answer
Explanation: The quantity of calgon to be added to prevent scale and sludge formation is 0.5-5 ppm. It is used in small quantity.
5. At high temperature and pressure, calgon is converted into sodium ortho-phosphate which reacts with ____________ salts.
a) Magnesium
b) Calcium
c) Sodium
d) Potassium
View Answer
Explanation: At high temperature and pressure, calgon is converted into sodium orthophosphate which reacts with calcium salts to form calcium ortho-phosphate.
6. Calcium ortho-phosphate appears as loose sludge and thus can be removed by blow-down operation.
a) True
b) False
View Answer
Explanation: Calcium orthophosphate appears as loose sludge and thus can be removed by blow-down operation. It is formed by the reaction of sodium ortho-phosphate with calcium salts.
7. Calgon conditioning is not applicable for the prevention of ___________
a) Iron oxide only
b) Copper depositions only
c) Sulphurdioxide only
d) Iron oxide and copper depositions
View Answer
Explanation: Calgon conditioning is not applicable to the prevention of iron oxide and copper depositions. Calgon prevents limescale build-up in washing machines all over the world to protect the heating element, pipes and drum of the machines.
8. Iron oxide and copper depositions can be prevented by adding ___________ to the boiler water.
a) Calgon
b) Carbonate
c) EDTA
d) EBT
View Answer
Explanation: Iron oxide and copper depositions can be prevented by adding EDTA to the boiler water. Ethylenediaminetetraacetic acid (EDTA), is an amino poly-carboxylic acid and a colorless and a water-soluble solid.
9. Carbonate conditioning is not done in high pressure boilers because it may lead to caustic embrittlement.
a) True
b) False
View Answer
Explanation: Carbonate conditioning is not done in high pressure boilers because it may lead to caustic embrittlement. Caustic embrittlement is the phenomenon in which the material of a boiler becomes brittle due to the accumulation of caustic substances.
10. Which of the following is not used in colloidal conditioning?
a) Kerosene
b) Tannin
c) Agar-agar
d) Vinegar
View Answer
Explanation: Kerosene, tannin and agar-agar are used in colloidal conditioning. Vinegar is not used for this purpose.
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