Chapter 10, 11, & 12 - Hardness, Acidity, and Microorganisms

Question 1

Hardness

Answer 1

The amount of dissolved calcium and magnesium in the water

Question 2

Total hardness

Answer 2

Total concentration of divalent cations in water expressed as equivalent calcium carbonate

Question 3

Groundwaters usually are ____ and contain _______

Answer 3

Anerobic and contain reduced Fe2+ or Mn2+

Question 4

Hardness equation

Answer 4

What the water contains * Molarity (M) of some substance

Question 5

Impact of hard water on aquatic life

Answer 5

Hard water can limit the growth of plankton in ponds and limit fish growth. In hard water, some metal ions form insoluble percipitates and drop out of solution and then no available for organisms to take up. In general, the harder the water, the lower the toxicity of the metals to aquatic life

Question 6

Low acidity is sometimes associated with

Answer 6

Low productivity and biodiversity

Question 7

What mainly contributes to acidic waters?

Answer 7

CO2 and humic substances

Question 8

Acidity

Answer 8

The amount of strong base necessary to neutralize the H+ concentration in water

Question 9

How can we measure acidity?

Answer 9

Titrate a water sample from its initial pH to pH 8.3 with standard NaOH

Question 10

Acidity mitigation

Answer 10

Limestone, lime, and other alkaline materials are used to neutralize acidity in the water

Question 11

Cyanobacteria

Answer 11

Produce and release O2 as a byproduct of photosynthesis, cyanobacteria have converted the oxygen-poor, reducing atmosphere into an oxidizing one causing the “rusting of the earth.” Also produce cyanotoxins that are harmful to organisms

Question 12

Redfield ratio

Answer 12

C:N:P = 106:16:1

Question 13

Phytoplankton on water quality

Answer 13

Impacts the water’s pH, DO, and CO2 concentration

Question 14

What are the environmental effects on bacterial growth?

Answer 14

Temperature, oxygen, carbon dioxide, pH, light, moisture, mineral nutrients etc.