Chemistry Project

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Lab_12.docx

Lab #12: Water

Purpose

In this activity you will learn about water treatment and water hardness. In the first part of the lab you will view some videos on water treatment and answer questions. In the second part of the lab you will test for water hardness in your home.

Video 1: Twin Cities Waste Water Treatment video

https://www.youtube.com/watch?v=D1aABVbI4JE

Watch this 15 minute video on sewage treatment in the metro area and answer the following questions:

1. What happened to St. Paul waste water prior to 1938? Why did this become a problem?

2. What does MCES stand for and what do they do today?

3. Where does waste water go directly after you flush or use the sink?

4. What percent of the Twin Cities metro area waste water does the Metro plant treat?

5. In primary treatment, what is an example of “floatable” material?

6. In secondary treatment, what does the brown color of the wastewater come from?

7. What is the last stage of the treatment process?

8. How often are water samples taken and tested?

Video 2: Testing for water hardness in your home

https://www.youtube.com/watch?v=jDgSohKVLio

1. Using your text, what ions are usually present in hard water?

2. What are some problems that can occur if your water is too hard?

3. Collect two water samples from your home. Obtain one sample from the kitchen sink and another sample from the bathroom sink. Test the water with dish soap as described in the video. Take a picture of your water samples immediately after shaking.

a. Describe what you see for your water sample from the kitchen. How hard is the water?

b. Describe what you see for your water sample from the bathroom. How hard is the water?

c. Do you know if your water is treated with a water softener? Check your faucets to see if there is evidence of hard water build-up. Do your observations match with what you determined in parts (a) and (b)?