Testing Your Tap Water Lab
LaMotte Tapwater Tour Test
NAME:______DATE:______
INTRODUCTION
Rarely is water just plain old H2O. The water that comes out of your taps has many other minerals contained in it. Most are not harmful and the one that may be harmful are controlled by the Safe Drinking Water Act. The source of most tap water in Audubon is the Potomac-Raritan-Mogohthy Aquifer System (groundwater). There are also times when Delaware River water is mixed in.
Before coming to your home the water goes to a drinking water treatment facility and is tested by water quality scientists. The test results from these scientists are posted online. (Mr. Manskopf will show you a recent report) This is all done to ensure that your water is safe to drink, tastes good, and won’t damage plumbing.
In this lab, you will play the role of water quality scientists and analyze some of the substances contained in your tap water.
STEP 1: COLLECTING THE WATER
Procedure
1)Rinse out a small plastic or glass jar, cup, or bottle (do not use soap, only tap water)
2)Let the cold water run for about a minute
3)Fill the jar, cup or bottle with about a cup of water
4)Cap jar, cup or bottle
5)Write your name and date on jar, cup or bottle
6)Bring it to school
STEP 2: TESTING pH
Introduction
pH is the measure of how acidic or basic things are. The scale runs from 0 to 14. 7 is neutral like pure distilled water. From 0 to 6.9 is an acid. From 7.1 to 14 is a base. Look over the pH chart found near the end of this lab packet.
Pre-Questions:
1)Predict what the pH of your tap water will be.
2)What is the approximate pH of rain water?
Materials: tap water sample, test bag, pH test tablet, straw
Procedure:
1)Fill the bag to line C with your tap water
2)Remove one pH test tablet from the foil strip and place it into the bag
3)Roll the bag down 3-4 times and fold yellow tabs back making to tight connection
4)Holding top of bag shake to dissolve the tablet
5)Compare the color of the reaction to the pH section of the color chart poster in front of room.
6)Record your results below
7)DO NOT THROW AWAY YOUR TEST YET!!!
8)Open bag slowly and blow into sample with straw for 2 minutes (DO NOT DRINK)
9)Record any changes to pH
10)Dump out solution and clean bag for reuse in next activity
Results and Questions
1)What was your initial pH of your tap water?
2)How did the pH change after blowing into it?
3)When you exhale, it contains a lot of Carbon Dioxide (CO2). Does CO2 make the water more acidic or basic?
4)As we add more CO2 to the atmosphere, how might our oceans change as they absorb CO2?
STEP 3: Measuring Chlorine
Introduction:
Chlorine is not naturally found in water. Chlorine is added at water treatment facilities to kill harmful bacteria and viruses. Too much chlorine can be deadly, taste badly and can irritate your skin. The average swimming pool has twice as much chlorine as your tap water. The bleach added to laundry has 15,000 times more chlorine as drinking water.
Materials:tap water sample, chlorine test tablet, test bags
Procedure:
1)Fill test bag to line C with your tap water sample
2)Add one Chlorine (DPD #4) Test Tablet
3)Close bag well and shake until tablet is dissolved
4)Compare color change to poster in front of room
5)Record results below
6)Dump solution and clean out bag for reuse
Results:
1)Was your tap water high or low in chlorine?
2)If we added bleach to your tap water, how would that change your results?
STEP 4: Iron in Your Water
Introduction:Iron (Fe) is naturally found in most water. Too much iron can stain sinks, tubs and clothes. Sometimes iron metal reacts with oxygen to form rust (Fe2O3). The orange-brown color of rust in a tub, sink or on clothes after washing can be an indicator of too much iron in your water.
Materials: tap water sample, iron test tablet, test bags
Procedure:
1)Fill test bag to line C with your tap water sample
2)Add one Iron Test Tablet
3)Close bag well and shake until tablet is dissolved
4)Compare color change to poster in front of room
5)Record results below
6)Dump solution and clean out bag for reuse
Results:
Was your tap water high or low in iron?
What color often indicates high amounts of iron?
STEP 5: Copper In Tap Water
Introduction: Small amounts of copper are found naturally in water. Sometimes people put copper in water to control the growth of algae. Copper can also be found in water from copper piping in your home. Sometimes people with too much copper in their homes have blue-green (color of Statue of Liberty) in tubs and sinks. Copper in water can also leave a bitter taste.
Materials: tap water sample, copper test tablet, test bags
Procedure:
1)Fill test bag to line C with your tap water sample
2)Add one Copper Test Tablet
3)Close bag well and shake until tablet is dissolved
4)Compare color change to poster in front of room
5)Record results below
6)Dump solution and clean out bag for reuse
Results:
1)Was your tap water high or low in copper?
2)What is the Statue of Liberty made from?
STEP 6: Hardness of Tap Water
Introduction:
Nobody thinks of water as being “hard.” When scientists describe the water as being “hard” we mean it has a lot of calcium and magnesium minerals dissolved in it. Hard water may be responsible for spots in drinking water glasses, white crusty scales on shower heads and even rings found in tubs.
Materials: tap water sample, hardness test tablet, test bags
Procedure:
1)Fill test bag to line A with your tap water sample
2)Add one Total Hardness Test Tablet
3)Close bag well and shake until tablet is dissolved
4)Compare color change to poster in front of room
5)Record results below
6)Dump solution and clean out bag for reuse
Results:
Was your tap water hard or soft?
Explain what it means to water scientists if the water is “hard?”
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