Chemistry - Study Mode

[#481] The metallic constituents of hard water are :
Correct Answer

(C) Calcium, magnesium and iron

Explanation

Solution: Hard water is water that has high mineral content. In domestic settings, hard water is often indicated by a lack of suds formation when soap is agitated in water. Wherever water hardness is a concern, water softening is commonly used to reduce hard water’s adverse effects. Water’s hardness is determined by the concentration of multivalent cations in the water. Multivalent cations are cations (positively charged metal complexes) with a charge greater than 1+. Usually, the cations have the charge of 2+. The metallic constituents of hard water are Calcium, magnesium and iron.

[#482] Potassium Permanganate is used for purifying drinking water, because________
Correct Answer

(B) It is an oxidising agent

Explanation

Solution: Potassium permanganate is a point-of-entry treatment method that oxidizes dissolved iron, manganese, and hydrogen sulfide into solid particles that are filtered out of the water. It can also be used to control iron bacteria growth in wells.

[#483] Lead in water can cause
Correct Answer

(C) Kidney damage

Explanation

Solution: Lead in water can cause kidney damage.

[#484] Hardness of the water is commonly measured in terms of
Correct Answer

(A) Calcium carbonate equivalents

Explanation

Solution: Hardness of the water is commonly measured in terms of calcium carbonate equivalents.

[#485] Maximum permissible concentration of copper in drinking water in mg/L is
Correct Answer

(C) 1.0

Explanation

Solution: The 1959 WHO International Standards for Drinking Water suggested that concentrations of copper greater than 1.5 mg/litre would markedly impair the potability of the water. However, in the first edition of the Guidelines for Drinking Water Quality, published in 1984, a guideline value of 1.0 mg/litre was established for copper, based on its laundry and other staining properties.