Category Archives: Grade 9

Sep 23 2015

Oobleck Lab

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The other day in Science 9 Honours, we experimented with a substance called Oobleck. ,Oobleck is made out of corn starch and water. We mixed the two together, and then started playing with the mixture. When we hit the mixture firmly, it was solid. When we put our fingers in it slowly, it was liquid. The mix also had a weird smell to it. We tried forming it into a ball, but it kept turning liquid and slipping away.

Here is the link to the photos and video we took:

https://drive.google.com/open?id=0ByUCLrRxozTYRml0VFhOOWtHdGM

Sep 21 2015

Laundry Detergent Lab

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Title: Cleaning Detergent Lab

 

Aim: To find out which laundry detergent has the best cleaning power.

 

Hypothesis:Which laundry detergent has the best cleaning power?

 

Prediction: Tide will have the best cleaning power (Stan believes that Woolite is for more delicate clothing).

 

Materials:

Five pieces of approx. 5x5cm rags stained with dirt, five beakers, five glass rods, tape (To label beakers), red sharpie, thumbtacks, 4 kinds of detergent, water, stopwatch.

 

Procedure:

First, cut out 5x5cm pieces out of a dirty rag. Fill five beakers with 250mL of water, then add 5 drops of different detergent to each one. After that, label each beaker according to the detergent in it. Next, put one rag into each beaker and stir each one for 70 seconds. Let them sit in the water for 10 minutes. Then, take the rags out of their beakers and pin them up to dry completely.

 

Observations:

  • Water(1): When the rag entered the water and was stirred, the water seemed to become dirtier. Pieces of fabric and dirt are falling off of the rag.
  • Ultra(2): The water looks very clean and transparent. No dirt is falling off of the rag. Only pieces of fabric. The water seems to be turning to a tint of red. We assume it is because of the Sharpie.
  • Sunlight(3): The water is much more dirty than the rest of the test subjects. Like swamp water, it is not see-through. Many dirt particles are falling off, but there are very little pieces of fabric.
  • Tide(4): The water is reddish-brown, which we think is the result of both the dirt and Sharpie washing off.
  • Woolite(5): The water is dirty, but not as dirty as Sunlight and Tide.The rags are pinned up and drying, and currently the rag that was washed with just water seems the cleanest.

The rags are now dry. Comparing the before and after pictures, we observe that number 3(Sunlight) and number 5(Woolite) are the cleanest. I believe that Woolite did the best job.

 

Photographs:

See link: https://drive.google.com/folderview?id=0ByUCLrRxozTYRFRmbzZRWG5nSk0&usp=sharing

 

Conclusion: Woolite does the best cleaning job on dirt.

 

Interesting Questions:

  • Would another detergent work better on a different stain, like coffee or berries?
  • Would the results differ if we had stirred each sample in the glass longer? Shorter?
  • Did the material of the sample affect the results significantly? Would the results be different if we used something cotton, and not a towel?