Monday, 23 January 2012
Sunday, 1 January 2012
Investigation Project Discovery
Investigation Project: Complex
Title: Stain Removal Project
Testable Question: Which is the best cleaning agent for removing stains?
What I changed (Independent variable): cleaning agents
What stayed the same (Controlled Variables): kind of fabric, type of stain, washing procedure
What I measured: (Dependent variables): the visibility of the stain after washing
Research:
I started my research by talking to mummy who is a teacher. She said that besides using commercial products, household items such as vinegar and baking soda also make good cleaning products. She also warned me never to mix vinegar with products containing ammonia as this could produce harmful vapors!
Hypothesis:
Vinegar and baking soda mixed together are best for removing stains from cotton fabric.
Why I think so:
I think this because the carbonic acid that results from mixing the two substances together probably breaks down stains.
Materials
Mustard
Blueberry syrup
Ketchup
Prune juice
Water
Vinegar
Baking soda
Commercial pre-stain treatment
Commercial laundry detergent
Q-tips
Watch/timer
Plastic cups for washing fabric swatches
100% cotton fabric swatches (approximately 3 inch squares)
Permanent marker for labeling
Procedure:
1. Cut at least 28 pieces of 100% cotton fabric into approximately 3 inch squares.
2. Use a permanent marker to label each of the fabric pieces using all of the combinations of stain and detergent mixture. (stains= ketchup, mustard, blueberry syrup, prune juice; detergent mixtures=water, vinegar, vinegar and baking soda, commercial pre-treatment, commercial laundry detergent, vinegar and baking soda paste +laundry detergent, commercial pre-treatment + laundry detergent.
3. Place a stain on each sample according to the labels.
W=water (50mL)
V=vinegar (50mL)
V+bs=vinegar +baking soda solution (30mL vinegar/20mL baking soda)
pst+w=commercial pre-stain treatment +water
(20mL commercial pre-stain treatment +30mLwater)
ld=laundry detergent +water (20mL laundry detergent+30mL water)
vbp+ld=vinegar, baking soda paste + laundry detergent
(10mLvinegar+40mL baking soda)+(20mL laundry detergent +30mL water)
cpst+ld= commercial pre-stain treatment + laundry detergent
(20mL commercial pre-stain treatment +30mLwater) + (20mL laundry detergent+30mL water)
1. Place each sample in the detergent mixture and scrub for 2 minutes.
2. Remove excess liquid and compare the samples when they are dry.
Data Table:
Stain Removal Effectiveness Scale:
5= highly effective (stain gone) 4=slightly visible 3= faded 2=no change 1=worse Stain Removal Data
| |||||
Mustard
|
Blueberry
|
Ketchup
|
Prune Juice
| ||
Water
|
1
|
3
|
2
|
4
| |
Vinegar
|
3
|
3
|
2
|
4
| |
Commercial laundry detergent
|
4
|
5
|
3
|
5
| |
Vinegar and Baking soda solution
|
1
|
2
|
2
|
3
| |
Commercial Pre-stain treatment with water
|
4
|
5
|
3
|
5
| |
Pre-stain vinegar and baking soda paste and commercial laundry detergent
|
5
|
5
|
4
|
5
| |
Commercial Pre-stain treatment with Commercial Laundry Detergent
|
4
|
5
|
5
|
5
| |
Qualitative Observations:
In most every example, the stain got at least a little bit lighter. However, some stains actually got worse when put in the different solutions. For example, the mustard stain actually got darker gold when put in vinegar and baking soda solution. The blueberry syrup stain turned green and brown when put in the vinegar and baking soda solution.
on Stain Removal Effectiveness Scale*
| |
Water
|
2.5
|
Vinegar
|
3.0
|
Commercial laundry detergent
|
4.25
|
Vinegar and Baking soda solution
|
2.0
|
Commercial Pre-stain treatment with water
|
4.25
|
Pre-stain vinegar and baking soda paste and commercial laundry detergent
|
4.75
|
Commercial Pre-stain treatment with Commercial Laundry Detergent
|
4.75
|
Results/Conclusions:
The results show that the best way to remove stains is to use either a combination of vinegar and baking soda paste + commercial laundry detergent or to use a combination of commercial pre-stain treatment + laundry detergent. Both of these treatments scored a mean average of 4.75 on the effectiveness scale (5 being the most effective).
My hypothesis was only partly accurate. I thought that just washing the stain in a vinegar and baking soda solution would be enough to remove the stain. What I found was that using more baking soda to make vinegar and baking soda paste then combining it with laundry detergent was the best way to remove most stains. This even worked better than using the laundry detergent alone or the commercial pre-stain treatment alone.
Since the commercial pre-stain treatment combined with laundry detergent did not appear to remove stains any more effectively than the homemade vinegar and baking soda paste + laundry detergent, I would recommend people purchase baking soda and vinegar since it is the cheaper and more eco friendly product.
Scientific Investigation Discovery
Investigation Project
Title: Keep it Cool
Testable Question: Which is the best insulator for keeping ice cold?
What I changed (Independent variable): The insulators (aluminum foil, Styrofoam, commercial plastic insulator, and no treatment)
What stayed the same (Controlled Variables): initial amount of ice, containers, time, location of the containers
What I measured: (Dependent variables): how much water melted from the ice over time
Research:
I started by looking up insulators in a book at my house. The book was called How Science Works by Judith Hann published by Reader’s Digest 1991. The book said that materials that trap air like polystyrene and wool are good insulators. Metals like aluminum are good at conducting heat. A thermos is good at keeping things cold because it cuts down on the passage of heat in all possible ways. Inside a thermos is a flask with a double wall of glass or plastic with a vacuum in between. The vacuum is good for stopping heat from passing through it.
I wasn’t sure if a book published in 1991 had the latest information about my topic, so I searched the internet to see if other current scientists still agree. After searching the internet, I found that polystyrene or Styrofoam is still good at keeping things cold. Finally, I asked the manager at the local convenience store. He said that Styrofoam coolers are one of his most popular products.
Hypothesis:
Styrofoam is the best insulator for preventing ice from melting.
Why I think so: I think this because my research says that polystyrene traps air and Styrofoam coolers are a very popular cooler to purchase.
Testable Question
|
What is tested
(independent variable)
|
What says the same (controlled variables)
|
Data Collected (dependent variable)
|
Which is the best insulator for keeping ice cold?
|
The insulators (aluminum foil, Styrofoam, commercial plastic insulator, and no treatment)
|
initial amount of ice, containers, time
|
how much water melted from the ice over time
|
Materials:
Styrofoam
Aluminum foil
Plastic commercial product (drink cozy)
Ice 300g
Clock/timer
4 transparent plastic cups with lids
Clay
Scale for determining mass
Measuring tool for mL
Time: 1 day
Procedure:
1. Place 75 grams of ice into each of 4 identical transparent plastic cups. Cover with lid. Cover the opening where the straw hole is with clay to make it airtight.
2. Insulate 3 of the cups with either aluminum foil, Styrofoam, or a plastic commercial insulator. Do not put any insulation on one of the cups.
3. Wait one hour. Remove the clay and pour the water from the cup. Measure the amount of water in each cup. Compare the amounts of water.
4. Measure and compare again every hour for 5 hours. Observe the ice and make qualitative observations as well.
Data:
The chart below shows how much water I collected after each hour. Amount of Melted Water Collected Over Time in mL
| |||||
Type of insulator
|
After
1 hour
|
After
2 hours
|
After
3 hours
|
After
4 hours
|
After
5 hours
|
Aluminum foil
|
5mL
|
20mL
|
15 mL
|
12mL
|
10mL
|
Plastic
|
10mL
|
20mL
|
18mL
|
12mL
|
15mL
|
styrofoam
|
10mL
|
20mL
|
11mL
|
15mL
|
10mL
|
none
|
15mL
|
20mL
|
20mL
|
20mL
|
--
|
Qualitative notes: As the ice cubes began to melt they stuck together. At the end of the 5 hours, there clearly was a bigger piece of ice left in the aluminum foil covered cup than in any of the other cups
Results and Conclusion
The results did not confirm my original hypothesis. I thought that the Styrofoam would be the clear winner. Instead the container with the aluminum foil had the most ice left at the end of the test. The Styrofoam came in second place, followed by the plastic and the container with no insulation.
I wonder if my results had something to do with the procedure I used. The loose Styrofoam that I placed around one of the cups may have let in more air than the aluminum foil that covered the other container completely. If I had to do the experiment again, I would use a Styrofoam cup instead of the smaller pieces of Styrofoam.
Also, since the difference between the Styrofoam and the aluminum foil was not that much, there could have been a slight error in how much ice I measured at the beginning of the experiment. Maybe the styrofoam cup had slightly less grams of ice at the beginning of the investigation because some of the ice could have been accidentally dropped when moving it from the scale to inside the cup. Maybe the ice in one of the containers began melting together when I was measuring it at the beginning of the investigation and this affected the rate of melting more than if the ice cubes were still cold and separate at the beginning of the experiment. My best guess for the different results is that it might have taken me too long to measure the melted ice resulting in more air getting inside the Styrofoam container than in the aluminum foil container.
While the results of my investigation show that aluminum foil is best for keeping things cold, I am not confident that my original hypothesis is totally wrong. The small differences at the end of the investigation make me think that repeating the investigation would help draw a more firm conclusion.
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