Water Unit

Physical Properties of Water

• Adhesion/Cohesion/ 
• Density
• Heat Capacity

Physical Properties of Water

• Surface tension
• States of water
• Suspended Sediment

Chemical Properties of Water

• Conductivity 
• Concentration Gradient

Water Quality Index

Nine Tests

• What is the test?
• How do you do it?
• Why test for this?

Dissolved Oxygen

• Gaseous Oxygen is dissolved into water.
• Collect sample, compare to charts.
• DO needed for aquatic life.

Fecal Coliform

• Tests for bacteria
• Mix sample with Lactose broth
• Look for yellow or green color

pH

• Test for basicict and acidity of water
• Use pH test strips
• Acidic water can kill organism

Temperature

• Measure with a thermometer and two samples
• temp affects photosynthesis, metabolic rates, presence of parasites
• Altered temp can affect local species

Nitrates

• Nitrogen levels in water
• Too much nitrates = undrinkable
• May signal presence of dead or decaying organisms
• Look for color change in samples after indicator

Phosphates

• Phosphorus test
• Test by indicato
• Needed for plant growth
• Too much and too little are unhealth