Water Chemistry

Measuring water chemistry in a river is like doing blood tests for a person.

Part 1: What is Water Chemistry?

Read page 1 of the Water Chemistry document.

In your journal, please respond to the following prompts.

• 1. Aside from the chemical components, what are the other two vital components of a water system such as a river?

  2. What are three different ways substances can get into river water?

  3. What are four areas of water chemistry that are often tested?

  4. What is one interesting fact about water that you read on this page?

Optional: Use this Water Chemistry notes template.

Part 2: pH

First, read pages 6-7 (labeled "Field 95-95") of the Water Chemistry document.

• In your journal, copy the table below. 

• Write a prediction for what pH (0 to 14) you think each of the 8 substances will be. 

• Test each substance with a pH strip and write the actual pH.

• Write whether this substance is acid, base, or neutral.

Part 3: Dissolved Oxygen (DO)

Observe the demonstration of the amount of dissolved gas that can be in hot liquid versus in cold liquid.

Read pages 11-12 (labeled "Field 100-101") of the Water Chemistry document.

In your journal, write and complete the following sentence.

"Cold liquid holds ________ (more or less) dissolved oxygen than hot liquid."

Part 4: Turbidity

Read pages 15-16 (labeled "Field 104-105") of the Water Chemistry document.

Observe the demonstration of the turbidity tube.

In your journal, copy the following notes.

Turbidity = how cloudy the water is.

A high level of turbidity:

• Clogs fish gills,

• Smothers fish eggs,

• Decreases oxygen,

• Heats up the water

• Makes it hard for animals to see

Part 5: Salinity

Salinity is the amount of salt in water.

In your journal, write the following two sentences.

Saltwater is more dense than freshwater.  Saltwater from the sea will sink below freshwater from a river when they meet in an estuary.