A Solution to Pollution

12/9/2010Acid Pollution and the Chicago River

System

Explore an acid pollution problem, and identify what needs to be known to solve it.◦ Identify the pH of several standard household

solutions◦ Describe the pH scale, and identify regions of the

scale as acidic, basic, or neutral.◦ Predict what would need to be added to a solution

to make it more acidic or basic.

Objectives

Chicago River, 1860

Chicago River, Present Day

There are different ways to measure the health of a river.

pH is one quick and easy way to tell if the waters are too hostile for living systems.

Why might too high or too low a pH be dangerous for living things?

River Chemistry

As scientists of the Environmental Protection Agency, you need to figure out what to do in a situation where a low pH might pose an environmental hazard.

Your Challenge

Read through the scenario in small groups

What words/ideas from the article do you want more information about?

What questions do you need answered before you make a decision about allowing C-Chip to dump wastes into the river?

Chicago Sun Times: City Officials Meet with C-Chip

Bacteria

Plants (algae, rooted)

Carp, catfish, some insects

Bass, bluegill

Snail, clams

Largest variety of animals

pH Ranges of Living Organisms in River EcosystemAcidic

See if you can identify the pH of these common household solutions!

Which is more acidic? Which is more basic?

Name that pH!

What are acids/bases?

Strong Acid: HCl (in water) Cl⁻+ H⁺Strong Base: NaOH (in water) Na ⁺ + OH ⁻

There is a difference of 10, in the change of H+ concentration (LOG)

Write down what happens when an acidic or basic substance is placed in water…

When an acid or base is placed into water, the molecules separates into ions.

Strong Acid… HCL: H+ and Cl-

Strong Base… NaOH: Na+ and OH-

Demonstration

pH= Power of HydrogenACID BA

SE

Neutral:concentration of Hydrogen Ions= Hydroxide Ions

Given a solution, how might you make it more acidic/basic/neutral?

Back to our Problem

Acidic Waste Water

Neutral Chicago River Water

Complete Questions 1 and 2 on the C-Chip Challenge Hand-Out.

Bring back signed Field Trip and Consent Form

Homework