Chemistry Module 3: Water Analysis and Purification

What is the purest form of naturally occurring water?

Rain water

What type of impurities can cause turbidity and give smell or odor to water?

Suspended impurities

What is the main characteristic of lake water in terms of impurities?

It has a constant composition of impurities

What is the most impure form of water?

Sea water Signup and view all the answers

What can be removed by filtration from water?

Suspended impurities Signup and view all the answers

What type of impurities include CO2, Cl2, H2S, SOx, and NOx?

Dissolved gases Signup and view all the answers

What can be added to neutralize the acidity produced by corrosion in boilers?

Alkalinity Signup and view all the answers

What is the primary reason for the formation of sludge in boilers?

Greater solubility of salts in hot water than in cold water Signup and view all the answers

What is the main disadvantage of sludge formation in boilers?

It wastes a portion of the heat generated Signup and view all the answers

Where is sludge typically formed in a boiler?

In areas of low water circulation Signup and view all the answers

What happens when sludge is formed along with scales in a boiler?

Sludge gets entrapped in scales and gets deposited as scales Signup and view all the answers

What is the result of excessive sludge formation in a boiler?

Decreased efficiency of the boiler Signup and view all the answers

What is the formula to calculate the CaCO3 equivalent of a dissolved salt in water?

Equivalent wt.Of CaCO3 × Amt.of salt given / Equivalent wt.of the salt Signup and view all the answers

What is the unit of measurement for expressing CaCO3 equivalent hardness, which is equal to 1 milligram of CaCO3 equivalent hardness present in 1 liter of water?

Milligrams per liter (mg/lit) Signup and view all the answers

What is the primary contributor to the hardness of water?

Bicarbonates, sulphates, chlorides, nitrates, of Ca, Mg and other heavy metals Signup and view all the answers

What is the complexing agent used in the EDTA method of determining water hardness?

Ethylene Di-amine Tetra acetic Acid (EDTA) Signup and view all the answers

What is the relation between milligrams per liter (mg/lit) and parts per million (ppm) units of expressing CaCO3 equivalent hardness?

1 mg/lit = 1 ppm Signup and view all the answers

What is the formula of the Metal-EDTA complex formed in the EDTA method?

(n – 4) Metal-EDTA complex Signup and view all the answers

What is the purpose of percolating hard water through a zeolite bed in the zeolite process?

To soften water by removing calcium and magnesium ions Signup and view all the answers

What happens to the zeolite when it is completely converted into calcium and magnesium zeolite?

It gets exhausted and unable to soften water further Signup and view all the answers

What is the purpose of treating the zeolite bed with a concentrated brine solution during regeneration?

To convert calcium and magnesium zeolite back into sodium zeolite Signup and view all the answers

What is an advantage of the zeolite process for softening water?

It is a clean process that requires less time for softening Signup and view all the answers

What is the hardness of the soft water obtained through the zeolite process?

5 - 10 ppm Signup and view all the answers

What is a limitation of the zeolite process?

The limitation is not specified in the text Signup and view all the answers

Why should turbidity and suspended matter be removed from water before zeolite treatment?

To prevent clogging of the zeolite bed and reduction of flow rate Signup and view all the answers

What is the preferred pH of water passing through a zeolite softener?

pH 7 Signup and view all the answers

Why can't water containing Fe+2 and Mn+2 be used for zeolite treatment?

The zeolite cannot be regenerated easily with brine Signup and view all the answers

What is the ideal quality of boiler feed water?

As pure as distilled water Signup and view all the answers

What is used as a softener in the demineralization process?

Ion exchange resins Signup and view all the answers

What is the characteristic of ion exchange resins that enables ion exchange?

Their functional groups attached to the chain Signup and view all the answers