Engineering Chemistry MCQ (R, S- Configuration and Water Softening)

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Engineering Chemistry MCQ (R, S- Configuration and Water Softening)

1. Which of the following is not a priority rule for R, S-Configuration?
a) If the four atoms attached to the chiral centre are all different, priority depends on atomic number, with the atom of lower atomic numbers getting lower priority
b) If the two atoms attached to chiral centre are same, the atoms attached to each of these first atoms are compared
c) When there is a double bond or triple bond, both atoms are considered to be duplicated or triplicated
d) If the four atoms attached to the chiral centre are all different, priority depends on atomic number, with the atom of higher atomic numbers getting lower priority
Answer: d
Explanation: If the four atoms attached to the chiral centre are all different, priority
depends on atomic number, with the atom of lower atomic numbers getting lower priority.

2. If our eyes travel in counter clockwise direction from the ligand of highest priority to the ligand of lowest priority, the configuration is ____________
a) R-Configuration
b) S-Configuration
c) E-Configuration
d) C-Configuration
Answer: b
Explanation: In S-Configuration, our eyes travel in counter clockwise direction from
the ligand of highest priority to the ligand of lowest priority.

3. According to the selection rules, the decreasing order of preference is __________
a) –NH2 > -C6H5 > -CH(CH3)2 > -H
b) –CH(CH3)2 > -C6H5 > -H> -NH2
c) –NH2 > -CH(CH3)2 > -C6H5 > -H
d) -C6H5 > -CH(CH3)2 >–NH2 > -H
Answer: a
Explanation: The atom of higher atomic numbers gets higher priority. So, –NH2 group has the highest priority of all.

4. The process of removal of hardness of water, irrespective of whether it is temporary or permanent is termed as __________
a) Cleansing action of water
b) Hardness of water
c) Softening of water
d) Purity of water
Answer: c
Explanation: The process of removal of hardness of water, irrespective of whether it
is temporary or permanent is termed as softening of water. This process includes
both temporary as well as permanent hardness.

5. The external treatment of water does not include __________
a) Lime-soda process
b) Sequestration
c) Zeolites
d) Ion-exchange process
Answer: b
Explanation: The external treatments of water include lime-soda, zeolites and ionexchange processes. It does not include sequestration.

6. Which of the following conditioning method is not used in internal treatment?
a) Colloidal
b) Calgon
c) Carbonate
d) Bicarbonate
Answer: d
Explanation: Colloidal, calgon, phosphate and carbonate conditioning methods are
used in internal treatment. Bicarbonate is not used for this purpose.

7. Select the incorrect statement from the following option.
a) Internal treatment is carried out outside the boiler before water enters into the boiler
b) Internal treatment methods are followed by blow-down operations
c) Internal treatment is required in low pressure boilers
d) Internal treatment is a corrective method
Answer: a
Explanation: Internal treatment is carried out inside the boiler. All the other options are correct.

8. External treatment is a preventive method and it is required in high pressure boilers.
a) True
b) False
Answer: a
Explanation: External treatment is a preventive method and it is required in high pressure boilers. External treatment is carried out outside the boilers.

9. Potable water treatment does not involve __________
a) Disinfection
b) Demineralisation
c) Coagulation
d) Sedimentation
Answer: b
Explanation: Potable water treatment does not involve demineralisation. It involves disinfection, coagulation and sedimentation processes.

10. The exhausted anion exchangers can be regenerated by working with __________
a) Acid solution
b) Alcohol solution
c) Alkali solution
d) Water
Answer: c
Explanation: The exhausted anion exchangers can be regenerated by working with alkali solution because alkali solution or basic solution does not contain reactiveions.