1. AIRING OUT OUR DIRTY LAUNDRY Kermit Green, Keith Verdi South Mountain Middle School Brainstorm Does having a water softener increase the effectiveness of your laundry detergent? Background Info Water is considered “hard” when it contains high amounts of dissolved minerals such as calcium and magnesium in it. These dissolved minerals build up in our appliances and interfere with the performance of laundry detergents and other household soaps. Installing a Water Softener in your home will remove these minerals from water and increase the life of your appliances and the effectiveness of soaps/laundry detergents. Experiment#2 Tap H 2 0 vs. Distilled H 2 0 in the Real World This is a repeat of experiment #1 with cotton cloths stained with grass and dirt and ketchup. We will observe each cloth to see which type of water is better for washing clothes. J Gelatin Cube Data Table Experiment #1 Gelatin Cubes in Tap H 2 0 vs. Distilled H 2 0 We placed equal sized Knox gelatin cubes in both types of water for 17hrs and measured the mass, volume, and density of the cubes. Set Up Experiment  Knox Gelatin  8oz plastic cups  Distilled water  Electronic balance  Metric Ruler  Plastic Knives  Plastic Spoons  100ml Graduated Cylinder  Arm and Hammer Liquid Detergent with Oxi clean Procedure 1.Cut three equal sized Knox gelatin cubes with plastic knife. 2.Measure mass with balance. 3.Measure the volume using metric ruler. 4.Determine Density 5.Fill 2 cups with 100ml of each type of water. 6.Place one teaspoon of Arm and Hammer in each cup of water and stir. 7. Place control in empty cup and remaining cubes in other cups. 8.Leave cubes in cups for approx 17hrs and measure mass, volume and density, Gelatin Cubes Answer the Question If you wash clothes without a water softener, the laundry detergent has to work “harder” to fight through these minerals and soften the water on its own and usually doesn’t have enough left to properly clean your laundry…unless you use a lot more detergent which doesn’t always get the job done. Analogy It’s kind of like a soccer player who has to jog 5 miles to his game instead of getting a ride. He uses a lot of energy jogging that he could have used for the game and therefore may not play as well. If he jogs to the game and gets there 2 hours earlier (using more detergent), he can then rest and build his energy back up, but still may not play as well as he could have had he gotten a ride. Variables Mineral Content of Water Stain type Temperature Agitation time Detergent brand and type (Liquid vs. powder) We choose to vary mineral content by comparing tap water to distilled water. ASK A QUESTION Will the use of distilled* (soft) water increase the effectiveness of l liquid laundry detergent vs. using tap water? *Distilled water is soft water without the sodium chloride. Predict An Outcome We predict that the laundry detergent will be more effective in the distilled water. As such laundry that is washed in distilled water should be cleaner than laundry washed in tap water. Gelatin CubesControlTap WaterDistilled Water Before/After 17 hours BeforeAfterBeforeAfter Mass in grams 17.14 19.9617.1519.68 Volume in cubic centimeters 17.13 2116.222.4 Density in grams per cubic centimeters 1.0.951.06.88 Set Up Experiment  Cotton Cloths  Generic Target Brand Ketchup  Plastic Spoons  100ml Graduated Cylinder  Arm and Hammer Liquid Detergent with Oxi clean  8oz plastic cups Procedure 1.Fill 4 cups with 100ml of each type of water. 2.Fill 2 cups with 100ml of tap water with no detergent, (these cups will be the controls). 3.Place one teaspoon of Arm and Hammer in each cup of water and stir. 4.Place stained clothes in each type of water. 5.Leave clothes in cups for approx 17hrs. 6.Stir for 2 minutes each. 7.Compare results. Cloths before soaking Set up of experiment Results The gelatin cubes increased in mass and volume, but decreased in density. This was due to the detergent causing the proteins to break up and spread out as part of the dissolving process. This happed at a greater rate in the distilled water. If we had left the gelatin in the laundry detergent longer, it would have eventually dissolved. Analogy It’s kind of like a skyscraper that is being imploded. Its volume will increase and density decrease before it is completely cleared and hauled away. The excess minerals in the tap-water interfere with the action of the enzymes in the laundry detergent. In distilled (soft) water, the enzymes were more effective in breaking down and removing the proteins in the grass and ketchup stains. See pictures above.