so most of us got o ur marking sheet back yesterday and discovered that our experiments were approved, mine included. congrats to everyone who did get their ones approved and have fun and good luck conducting your experiments. remember, safety first!
okay, this blog is appearing much later than i wanted it to but since i'm absolutely unorganised when it comes to schoolwork, i've been pretty busy/ lazy. this should be blog 10, but i guess blog 08 will have to do. back to the experiment. (i won't be elaborating any more on the m&m's experiment since my foam one has been approved but i might still look for new ideas in case this one doesn't work out.)
"which foods produce a good foam with high volume and longevity?"
the method is as follows:
1) Measure out one tablespoon of one of the test liquids.
2) Put on safety goggles.
3) Pour the test liquid into one of the test tubes and place on the rubber stopper so it is tight.
4) Hold the test tube vertically and mark the starting level of the liquid (the level of the top of the liquid).
5) Have a stopwatch ready at hand. When you begin to shake the test tube, start the stopwatch immediately.
6) Shake the test tube vigorously for 40 seconds.
7) Stop shaking at the 40 second mark and reset the stopwatch.
8) Hold the test tube vertically and make marks at the surface of the liquid and at the top of the foam.
9) Measure and record the distance between the starting level and the top of the foam.
10) Measure and record the distance between the starting level and the surface of the liquid.
11) Place the test tube in a test tube rack. A magnifying glass may be used to observe the size and uniformity of the foam's bubbles. Record observations.
12) At each time increment (later explained), repeat steps 9 and 10 until the trial is over (when there is no foam or when 30 minutes has passed).
13) Repeat steps 1 to 12 for each test liquid with the same number of trials for each test liquid.
i know this isn't the best method, so i'll be improving it later on. the results will be recorded in a table similar to this:
to test
the longevity of the foam, each trial will be left untouched after being shaken. after certain time increments the distance between starting level and the top of the foam and the starting level and the surface of the liquid will be recorded.
i would like to have at least
10 trials for each test liquid, maybe even 15. i'll do the experiment over several days that have around the same temperature so that i'll know that the results won't be affected by the temperature on the day. on the days, i'll do the same number of trials for each test liquid, so maybe one trial of each test liquid is experimented with on any one day. by doing this, at least one trial of all the test liquids will be conducted in the same conditions. oh, i remember thinking about temperature being another variable for the experiment but have since decided it would be way too hard, so yeah...
the website uses
test liquids such as tap water, milk, egg and diluted washing detergent. i might add or replace some test liquids that are common in everyday life. some people suggested coke and something else that i forgot...but coke sounded like a good idea. the test liquids that i am certain on so far are:
-water
-whole milk
-nonfat milk
-diluted washing detergent
i'll think about the egg because i know that egg whites are used to make meringue which consists of a lot of air. however, i don't want to have too many test liquids but not too little either.
i was totally confused over
the controlled, independent and dependent variables before, but my sister patiently explained so i think i've got the gist of it now. attempt number 2 at listing variables:
CONTROLLED-size of the test tube/ container
-amount of each liquid
-amount of time each trial is shaken for
-the strength at which the liquids are shaken at (i.e. not different shaking strengths for the trials)
-the temperature of each liquid before shaking (most likely room temperature)
-the time periods between each recording (foam longevity measurement)
INDEPENDENT-the type of liquid
DEPENDENT-the amount and longevity of foam
i think that's all of it, but i'll add more/ edit it later if i remember something.
