250+ TOP MCQs on Chemical Treatment – Precipitation and Answers

Hazardous Waste Management Multiple Choice Questions on “Chemical Treatment – Precipitation”.

1. Chemical precipitation makes the hazardous waste _________
a) Soluble
b) Insoluble
c) Volatile
d) Acidic
Answer: b
Clarification: Chemical precipitation causes soluble hazardous substances to insoluble matter which is separated from the solution.

2. Precipitation by ___________ is widely used method for treating hazardous waste.
a) Calcium hydroxide
b) Sodium hydroxide
c) Potassium hydroxide
d) Lead oxide
Answer: a
Clarification: Precipitation by calcium hydroxide is widely used method for treating hazardous waste. Addition of reagents cause reactions which precipitate undesired species.

3. Chemical precipitation is used in conjunction with neutralisation.
a) True
b) False
Answer: a
Clarification: By examining the chemistry of the waste composition chemical precipitation is used in conjunction with neutralisation and may require filtration unit.

4. Chemical precipitation treatment is effective in wastewater containing _______
a) Chemicals
b) Chloride
c) Toxic metals
d) Impurities
Answer: c
Clarification: Chemical precipitation treatment is effective in wastewater containing toxic metals such as arsenic, barium, cadmium, chromium, lead, copper, mercury, nickel and zinc.

5. _______ treatment is suitable for metal salts bearing wastes.
a) Neutralisation
b) Chemical precipitation
c) Hydrolysis
d) Solvent extraction
Answer: b
Clarification: Chemical precipitation treatment is suitable for metal salts bearing wastes, including neutral acidic and alkaline materials.

6. Precipitation of metals varies depending on _________ level.
a) Acidic
b) Basic
c) Neutral
d) pH
Answer: d
Clarification: Metals precipitate at varying pH levels depending on the metal ion, resulting in formation of insoluble salt.

7. _______ is used for precipitation of heavy metals.
a) Calcium hydroxide
b) Lime
c) Potassium hydroxide
d) Lead oxide
Answer: b
Clarification: The hydroxides or heavy metals are usually insoluble so lime or caustic soda is commonly used to precipitate them.

8. Chemical precipitation treatment is user economic.
a) True
b) False
Answer: b
Clarification: Chemical precipitation treatment is expensive process. Due to the 1 to 1 ratio, a large quantity of reagent is generally needed, which is often very costly.

9. The environmental issue caused by chemical precipitation is _________
a) Chemical silt
b) Salts
c) Liquid matter
d) Degradation
Answer: a
Clarification: Chemical silt is formed as a by-product of chemical precipitation treatment. Silt from heavy metal precipitation is regarded as dangerous waste.

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