Water Flashcards
1
Q
Hard water
A
water that will not easily form a lather with soap.Caused by Mg2+ and Ca2+ ions dissolved in the water.
2
Q
Temporary hardness
A
hardness that can be removed by the boiling of water. Magnesium hydrogen carbonate or calcium hydrogen carbonate.
3
Q
Permanent hardness
A
hardness that cannot be removed by boiling of water. Magnesium sulfate or calcium sulfate.
4
Q
Biochemical oxygen demand (BOD)
A
the amount of dissolved oxygen consumed by biological action when a sample of water is kept at 20C in the dark for 5 days.
5
Q
Eutrophication
A
enrichment of water with nutrients, leading to excessive growth of algae and other plants.
6
Q
Principle of colorimetry
A
the amount of absorbance of light by a coloured solution is proportional to the concentration of the solution.
