A. Calcium bicarbonate
B. Magnesium bicarbonate
C. Magnesium chloride
D. Calcium nitrate
E. Calcium sulphate
Choose the correct answer from the options given below:
Permanent Hardness Salts Identified
Permanent hardness in water is caused by the presence of soluble salts of calcium and magnesium, specifically their chlorides, sulphates, and nitrates. Temporary hardness, in contrast, is caused by bicarbonates.
Salt Analysis for Hardness
Let's analyze the salts mentioned in the options:
- Calcium bicarbonate (Ca(HCO3)2): Causes temporary hardness, removable by boiling.
- Magnesium bicarbonate (Mg(HCO3)2): Causes temporary hardness, removable by boiling.
- Magnesium chloride (MgCl2): Causes permanent hardness.
- Calcium nitrate (Ca(NO3)2): Causes permanent hardness.
- Calcium sulphate (CaSO4): Causes permanent hardness.
Identifying Correct Salts
Based on the analysis, the salts responsible for permanent hardness are Magnesium chloride (C), Calcium nitrate (D), and Calcium sulphate (E).
Therefore, the correct option includes C, D, and E only.
Important Questions from Water Treatment
In the flocculation method of water treatment ______ chemical is added to water.
Which of the following is NOT a chemical coagulant used in water treatment?
Which laboratory test is done to determine approximately the dosage of coagulant?
Statement I): Softening of clear groundwater should be carried out immediately after collection by pumping out, or from springs.
Statement II): Iron and manganese precipitates can foul the exchange medium surface if oxidation occurs in, or prior to, the ion-exchange phase.
Which process is used in water purification?
A. Osmosis
B. Reverse Osmosis
C. Cytolysis
D. Turgor pressure
