Water midterm

8 water parameters

1. pH

2. turbidity

3. conductivity

4. ammonia nitrogen

5. nitrate nitrogen

6. phosphates

7. dissolved oxygen

8. fecal coliform

conductivity

a measure of how well water conducts electricity

what affects the conductivity of water and why

salinity;

if salinity goes up, conductivity goes up because dissolved salts conduct electrical current

water hardness

measure of dissolved calcium and magnesium in water

hard vs soft water

hard water causes less bubbles (from lab)/ reduced lather and buildup (scum)

watershed

an area of land that drains all of its water to a specific lake or river

municipal water

tap water

estuary

the tidal mouth of a large river, where the tide meets the stream

ecological importance of estuary

• habitat

• breeding

• water quality

dependent variable

what changes as a result of the independent variable

independent variable

a variable whose variation does not depend on that of another

standard curve

shows the relationship between a substance’s concentration and its response

standard curve purpose

determine the concentration of an unknown substance by comparing it to a set of known concentrations

what does R² tell you about the standard curve

how well the data points fit the linear regression line

standard curve formula

y=mx+b

y = initial conductivity

m = slope of the graph

b = conductivity of distilled water

How can you make known solutions at different concentrations by dilution of a
stock solution?

Use dilution formula: C1V1 = C2V2

C1 = concentration of stock

V1 = volume of stock needed

C2 = desired final concentration

V2 = final volume of diluted solution

eutrophication

occurs when a body of water receives large inputs of nutrients, stimulating excessive primary production

How was dissolved oxygen related to phytoplankton growth?

phytoplankton are the primary producers of dissolved oxygen through photosynthesis;

DO increases with population growth

How was the phosphate level related to phytoplankton growth?

higher phosphate concentrations lead to increased phytoplankton growth

element

matter which cannot be divided into more than one substance

parts of an atom

• protons

• electrons

• neutrons

ionic bonds

one atom donates/accepts an electron(s) from another atom

electrons are transferred

covalent bond

electrons are shared between different atoms

polar covalent bond

unequal sharing of electrons

hydrogen bond

formed between the slightly negative oxygen end of a water molecule and the slightly positive hydrogen end of a different water molecule

what 2 types of chemical bonds are important in water?

1. covalent - oxygen + hydrogen bond in a single molecule

2. hydrogen - responsible for holding one water molecule to another water molecule

unique properties of water

1. universal solvent (stable, small molecules, polar)

2. cohesion/adhesion (water clings to self/other things)

3. high specific heat/ high heat of vaporization

4. less dense as a solid than liquid

how does temperature affect density?

temp goes up, density goes down due to fast movement of and distance of molecules

when is water most dense

4 degrees C (39 F)

process of seasonal turnover in a temperate freshwater pond such as
Pig Pen Pond

lake stratification;

In the spring turnover, warmer water rises as the surface heats up. In fall, surface waters cool, become denser and descend as heat is lost from the surface.