Wart-R Kem-East-Tree

Question 1

shifting chemical equilibria

Answer 1

-precipitation reactions, coagulation
oxidation / reductions reactions, removal of soluble ferrous ions
-Acid - Base reactions
-Gas productnig reactions, ammonia stripping

Question 2

Precipitation reactions

Answer 2

• forming of insoluble precipitates of undesirable substances by addition of treatment chemicals. use of aluminium sulfate to remove turbidity, use of lime to remove the multivalent ions of hardness
• precipitates are removed from suspension by gravity sedimentation and then filtration.

Question 3

Lime (CaO) softening

Answer 3

• Hard water (high in Ca 2+) tends to deposit scale on pipes and appliances.
• Addition of CaO raises pH to remove Ca 2+ from solution

CaO + Ca(HCO3)2 = 2CaCO3 + H2O
This results in a shift to the right

Question 4

Analytical methods

Answer 4

pH: pH meter gives direct reading correcting for T (temperature?)
Alkalanity and Acidity: Titration
Hardness: EDTA titrimetric method
Iron and Manganese: spectrophotometer