WorksheetsWater Treatment - AC I - UNIT I
Total questions: 10
Worksheet time: 5mins
The main purpose of external water treatment is to:
Remove hardness-producing salts
Remove dissolved oxygen
Neutralize acidity
Prevent boiler corrosion
In the zeolite process, hardness of water is removed by:
Adsorption
Ion exchange
Filtration
Sedimentation
The chemical formula of zeolite used in water softening is:
Na₂Al₂Si₂O₈·xH₂O
CaCO₃
Mg(OH)₂
NaCl
During the zeolite process, the hardness ions Ca²⁺ and Mg²⁺ are replaced by:
H⁺ ions
Na⁺ ions
OH⁻ ions
K⁺ ions
The exhausted zeolite is regenerated using:
NaCl solution
H₂SO₄ solution
Na₂CO₃ solution
NaOH solution
In the cation exchange process, hard water passes through a resin containing:
H⁺ ions
Na⁺ ions
OH⁻ ions
Cl⁻ ions
In a mixed bed deionizer, the cation exchange resin is followed by:
Anion exchange resin
Zeolite
Activated carbon
Sand filter
The function of the anion exchange resin is to:
Exchange Ca²⁺ and Mg²⁺ with Na⁺
Exchange Cl⁻ and SO₄²⁻ with OH⁻
Exchange Na⁺ with Ca²⁺
Remove suspended impurities
The final product of deionized water treatment (cation + anion exchange) is:
Distilled water
Demineralized water
Soft water
Portable water
The main disadvantage of the zeolite process is:
High cost of zeolite
It cannot remove acidic impurities or dissolved gases
Zeolite regeneration is impossible
Process produces hard water
