Wild Chemistry Ride 4 (part 2):
After successfully completing the Energy Tower task, I was better able to carry out a scientific experiment since I had experience from Sunken Treasure. As such I had a clearer plan and idea on what to do for the experiment, for example: building 5-spoke wheel+building tower--> testing out--> recording down data--> repeating 2 more times for reliability--> repeating whole experiment again but instead using 8-spoke wheel and so on.
My group mates and I had great teamwork this time as well, especially when we discovered in the middle of our experiment that our first plan did not work. Our original idea was to poke holes at different heights in a large bottle, cover the holes with tape and fill the bottle up with water, then remove the tape from each hole for each try and let the water spray onto the wheel. Thus we were planning to investigate if the height from which water is spraying out from affects the speed of the turbine. However, we came up with our second idea, which was to find out if a larger number of spokes on the turbine will affect the time taken for the weight to be lifted to 15cm.
Additionally, we discovered that we had to make the weight stop only at 15cm, thus we improvised and quickly made a simple stopper (two sticks) to ensure that the weight is lifted to a height of 15cm and nothing more.
However, I think we should make an effort to focus more on the task at hand. This is because for the past two experiments, despite us successfully completing the task, we could have been more efficient if we had been less distracted with playing with the materials.
Have a chem-tastic day!
Friday, 31 January 2014
Wild Chemistry Ride 4 (part 1):
Procedure:
1. Cut out 5 3cmx5cm rectangles from the plastic board
2. Use tape to attach the rectangles onto the tape-coated part of the towel roll to create even spokes, then secure the spokes to the towel roll with plasticine
3. Poke a hole through the width of the end of the second towel roll
4. Stick a wooden skewer through the hole
5. Stick 2 sticks at the 15 cm mark to act as a stopper (distance between sticks < width of 5g weight
6. Poke a hole through the width of the end of the second towel roll
7. Stick a wooden skewer through the hole.
8. Stick two sticks at the 15 cm mark to act as a stopper
9. Tape one end of the string to the tape-coated end of the first towel roll
Video: one of our successful set-ups!
Data Tabulation:
We were not able to …
Aim: To find out if a larger number of spokes will increase the time taken for the weight to be lifted to 15cm.
Hypothesis: The larger the number of spokes, the shorter the time taken to lift the weight to 15cm.
Hypothesis: The larger the number of spokes, the shorter the time taken to lift the weight to 15cm.
Independent Variable: the number of spokes
Dependent Variable: time taken for the weight to be lifted to 15cm
Controlled Variables: the mass of the weight, the length of the string from the wheel to the weight, size of each spoke, number of rotations of the sink handle thing
Assumptions: the speed of water flowing from the tap is consistent with every try, the (human error) reaction time is the same with every try
Materials Provided: (excluding the turbine and tower, though toilet rolls were given)
Procedure:
1. Cut out 5 3cmx5cm rectangles from the plastic board
2. Use tape to attach the rectangles onto the tape-coated part of the towel roll to create even spokes, then secure the spokes to the towel roll with plasticine
3. Poke a hole through the width of the end of the second towel roll
4. Stick a wooden skewer through the hole
5. Stick 2 sticks at the 15 cm mark to act as a stopper (distance between sticks < width of 5g weight
6. Poke a hole through the width of the end of the second towel roll
7. Stick a wooden skewer through the hole.
8. Stick two sticks at the 15 cm mark to act as a stopper
9. Tape one end of the string to the tape-coated end of the first towel roll
11. Stand the second roll up with the skewer at the top end
12. Secure the roll onto the bench
13. Guide the string from the first towel roll to over the skewer and between the two skewers below it
14. Tie the other end of the string to the weight
15. Position the turbine on the first roll horizontally across the sink and under the tap
16. Turn the tap on
17. Record the time taken for weight to be lifted to 15cm
18. Repeat 1-17 but make a 8-spoke turbine instead of a 5-spoke one
Time taken for the load to be lifted 15cm when using 5 spokes/ms
|
Time taken for the load to be lifted 15cm when using 8 spokes/ms
| |
Try 1
|
41
|
36
|
Try 2
|
30
|
38
|
Try 3
|
25
|
51
|
Average
|
32
|
42
|
*Note: We tested the reaction time by pressing the button three times and the result was 16ms for every try. Therefore 16ms was deducted from the time taken to derive the actual time taken for each try
Conclusion:
The smaller the number of spokes, the shorter the time taken for the weight to be lifted to the 15 cm mark.
Limitations:
1. Control the speed of the water gushing out from the tap, which will affect the the speed of the turbine
2. Measure and ensure that the total mass of plasticine added to the spokes for the 1st and 2nd try were the same, due to time constraints
3. Measure the degree/distance between each spoke exactly due to time constraints
Thursday, 30 January 2014
Wild Chemistry Ride 3 (part 2):
After the Sunken Treasure experiment, I learnt much more about carrying out a proper scientific experiment through a fun and meaningful way. For example, I learnt the difference between "observations" and "data collection": observations are the what you observe (such as see, hear, smell etc.), while data collection is about gathering and measuring information (such as the volume of gas collected in a gas syringe etc.)
Some scientific concepts I have learnt are when hydrogen peroxide (which I found out later was Solution 2) and the carrots' catalyse are physically combined, gas will be produced. Also I discovered that by chopping up the carrots into small pieces, the exposed surface area of the carrots to the salt and sugar solution will be increased, thus the reaction will occur within a shorter period of time.
Overall, I felt that my group worked together very well, as we each were given a role in the team, for example two were in charge of taking pictures and recording down observations and data, two were in charge of preparing the experiment apparatus and chopping up the carrots into very small pieces, while another group mate and I were mainly performing the experiments. However, all of us still contributed ideas to our plan and our teamwork was what I thought helped us in achieving success, and I am thankful for that.
On the other hand, my group mates and I could be less distracted by other things like playing around with the balloons, and also be less careless like when we often forgot to pump the air out of the gas syringe before using it again the next try.
*the ride coming up next… Energy Tower!
After the Sunken Treasure experiment, I learnt much more about carrying out a proper scientific experiment through a fun and meaningful way. For example, I learnt the difference between "observations" and "data collection": observations are the what you observe (such as see, hear, smell etc.), while data collection is about gathering and measuring information (such as the volume of gas collected in a gas syringe etc.)
Some scientific concepts I have learnt are when hydrogen peroxide (which I found out later was Solution 2) and the carrots' catalyse are physically combined, gas will be produced. Also I discovered that by chopping up the carrots into small pieces, the exposed surface area of the carrots to the salt and sugar solution will be increased, thus the reaction will occur within a shorter period of time.
Overall, I felt that my group worked together very well, as we each were given a role in the team, for example two were in charge of taking pictures and recording down observations and data, two were in charge of preparing the experiment apparatus and chopping up the carrots into very small pieces, while another group mate and I were mainly performing the experiments. However, all of us still contributed ideas to our plan and our teamwork was what I thought helped us in achieving success, and I am thankful for that.
On the other hand, my group mates and I could be less distracted by other things like playing around with the balloons, and also be less careless like when we often forgot to pump the air out of the gas syringe before using it again the next try.
*the ride coming up next… Energy Tower!
Monday, 27 January 2014
Wild Chemistry Ride 3 (part 1):
SUNKEN TREASURE
Experimental Design!: Our task was to lift a bottle full of marbles from a large basin of water without pulling it out using muscle power, inflating the balloon outside of the tank or inflating it using lung power. However, we were allowed to put our hands in the basin of water and tie/ attach any device we built to the hook-shaped wire attached to the treasure bottle.
Our aim was to find out which solution, 1, 2 or 3, will be able to create a chemical reaction that will be able to release enough gas to be able to inflate the balloon and lower the density of the bottle of marbles and balloon such that they will float.
We hypothesised that the mixture of a particular solution with salt and/or sugar and carrots will produce the most amount of gas, enough to inflate the balloon so the combined density of the balloon and the bottle of marbles will be lower than the density of the water such that the whole set-up will float to the surface.
First, how did we find out which solution reacts best? We used the dropper provided to fill each of 3 test tubes with one type of solution- 1, 2 or 3. Then we added a 1cmx1cmx0.5cm piece of carrot into the test tube. After observing the carrot and solution for 1 minute, we found out that Solutions 1 and 3 with the carrot had no visible reaction, while for the test tube filled with Solution 2 and the carrot, bubbles formed on the carrot and it floated to the surface. Thus we concluded that Solution 2 was the most suitable to use as it reacted best with the carrot among the 3 solutions.
The table below shows more observations we made...
Next, we poured another 15ml of Solution 2 into another test tube and added another 1cmx1cmx0.5cm piece of carrot plus a pinch of salt (although we should have weighed the mass of salt added to ensure that for every try we added the same amount of salt/ sugar), then we measured and recorded the volume of air collected after 2 minutes using the gas syringe. We repeated the steps here but this time we added a pinch of sugar instead, and for another try we added both a pinch of salt and a pinch of sugar. To ensure the reliability of our results, we repeated these steps twice.
After recording down our observations, we presented them in a table shown below...
Therefore, the most amount of gas was collected when we used the carrot and solution 2 with BOTH sugar and salt.
After finding out what mixture (salt, sugar, solution B and carrots) we should use for our set-up, we proceeded with the task. We first chopped carrots into as small pieces as possible, as we believed this would allow the carrots to have a greater exposed surface area to the solution, thus increasing the rate of the reaction occurring. Then, we filled a conical flask with Solution 2 and prepare balloon with the chopped carrots, salt and sugar. After stretching the balloon such that it covers the top of the conical flask without pouring the contents into the flask, we attached the conical flask to the treasure (the bottle of marbles) using wire. Next, we placed the set-up into the tank and poured the contents of the balloon into the conical flask.
^AND WE SUCCEEDED!
As such, we concluded that the mixture of Solution 2 with salt, sugar and carrots produced the most volume of gas and therefore was able to inflate the balloon and reduce the density of the bottle of marbles and balloon combined, successfully making the treasure float.
However, despite our success, we faced some limitations as well. Due to:
More will be up next… in my next post on my reflections after this experiment!
SUNKEN TREASURE
Experimental Design!: Our task was to lift a bottle full of marbles from a large basin of water without pulling it out using muscle power, inflating the balloon outside of the tank or inflating it using lung power. However, we were allowed to put our hands in the basin of water and tie/ attach any device we built to the hook-shaped wire attached to the treasure bottle.
Our aim was to find out which solution, 1, 2 or 3, will be able to create a chemical reaction that will be able to release enough gas to be able to inflate the balloon and lower the density of the bottle of marbles and balloon such that they will float.
We hypothesised that the mixture of a particular solution with salt and/or sugar and carrots will produce the most amount of gas, enough to inflate the balloon so the combined density of the balloon and the bottle of marbles will be lower than the density of the water such that the whole set-up will float to the surface.
First, how did we find out which solution reacts best? We used the dropper provided to fill each of 3 test tubes with one type of solution- 1, 2 or 3. Then we added a 1cmx1cmx0.5cm piece of carrot into the test tube. After observing the carrot and solution for 1 minute, we found out that Solutions 1 and 3 with the carrot had no visible reaction, while for the test tube filled with Solution 2 and the carrot, bubbles formed on the carrot and it floated to the surface. Thus we concluded that Solution 2 was the most suitable to use as it reacted best with the carrot among the 3 solutions.
The table below shows more observations we made...
Solution 1
|
Solution 2
|
Solution 3
| |
Carrot only
|
No visible reaction
|
Bubbles form on surface of carrot and float to surface
|
No visible reaction
|
Carrot+Sugar
|
No visible reaction
|
Many bubbles from the carrot
|
Few bubbles from the carrot
|
Carrot+Salt
|
Salt dissolves slowly
|
Salt dissolves super fast and the bubbles float to surface
|
Salt dissolves slowly
|
Control
(Solution only)
|
No visible reaction
|
Bubbles formed on surface of test tube
|
No visible reaction
|
Next, we poured another 15ml of Solution 2 into another test tube and added another 1cmx1cmx0.5cm piece of carrot plus a pinch of salt (although we should have weighed the mass of salt added to ensure that for every try we added the same amount of salt/ sugar), then we measured and recorded the volume of air collected after 2 minutes using the gas syringe. We repeated the steps here but this time we added a pinch of sugar instead, and for another try we added both a pinch of salt and a pinch of sugar. To ensure the reliability of our results, we repeated these steps twice.
After recording down our observations, we presented them in a table shown below...
Volume of gas collected/ml
| ||
Carrot + Sugar + Salt+ Solution 2
|
Carrot + Sugar+ Solution 2
|
Carrot + Salt+ Solution 2
|
3.0
|
1.5
|
0.5
|
Therefore, the most amount of gas was collected when we used the carrot and solution 2 with BOTH sugar and salt.
After finding out what mixture (salt, sugar, solution B and carrots) we should use for our set-up, we proceeded with the task. We first chopped carrots into as small pieces as possible, as we believed this would allow the carrots to have a greater exposed surface area to the solution, thus increasing the rate of the reaction occurring. Then, we filled a conical flask with Solution 2 and prepare balloon with the chopped carrots, salt and sugar. After stretching the balloon such that it covers the top of the conical flask without pouring the contents into the flask, we attached the conical flask to the treasure (the bottle of marbles) using wire. Next, we placed the set-up into the tank and poured the contents of the balloon into the conical flask.
^AND WE SUCCEEDED!
As such, we concluded that the mixture of Solution 2 with salt, sugar and carrots produced the most volume of gas and therefore was able to inflate the balloon and reduce the density of the bottle of marbles and balloon combined, successfully making the treasure float.
However, despite our success, we faced some limitations as well. Due to:
•Time constraints, we were unable to repeat the experiments to make ensure its reliability
•The small amount of salt and sugar given, we were unable to use more salt and sugar to create the chemical reaction even more to inflate the balloon bigger.
•The lack of proper measuring tools, we did not measure the sizes or mass of the carrot when chopping them for the balloon, however, we cut them as small as possible to have more surface area for reaction. Thus, it would have a greater effect than when we did the test solutions.
More will be up next… in my next post on my reflections after this experiment!
Wednesday, 8 January 2014
Wild Chemistry Ride 2:
Accuracy VS Precision
• Accuracy: how close your result is to the actual value
• Precision: how close your values are to each other
MYTHBUSTERS
• Video Time! (Diet Coke and Mentos) http://www.youtube.com/watch?v=LjbJELjLgZg
• What did the Mythbusters do?
- Researched on views from the media on the explanation of the explosion of Diet Coke when mentos was added to it
- Made an assumption that carbon dioxide was the cause behind the explosions
- Had a control set-up (bottle of soda water instead of Diet Coke) for comparison
- Experimented on different possible causes of the "explosion"
• Are the Mythbusters really scientists?
- According to the video, the data collection of the experiment was not shown, thus if there really was no data collection, then the Mythbusters would not be scientists. However, if all steps of a proper experiment (refer to Wild Chemistry Ride 1) were followed outside of the video, then the Mythbusters might be scientists after all. What do you think?
Accuracy VS Precision
• Accuracy: how close your result is to the actual value
• Precision: how close your values are to each other
MYTHBUSTERS
• Video Time! (Diet Coke and Mentos) http://www.youtube.com/watch?v=LjbJELjLgZg
• What did the Mythbusters do?
- Researched on views from the media on the explanation of the explosion of Diet Coke when mentos was added to it
- Made an assumption that carbon dioxide was the cause behind the explosions
- Had a control set-up (bottle of soda water instead of Diet Coke) for comparison
- Experimented on different possible causes of the "explosion"
• Are the Mythbusters really scientists?
- According to the video, the data collection of the experiment was not shown, thus if there really was no data collection, then the Mythbusters would not be scientists. However, if all steps of a proper experiment (refer to Wild Chemistry Ride 1) were followed outside of the video, then the Mythbusters might be scientists after all. What do you think?
Wild Chemistry Ride (aka lesson) 1:
Planning an Experiment
• Writing a hypothesis
• Identifying variables
- independent
- dependent
- controlled--> not "constant"
• Assumptions (they can be controlled and have a minimal effect on the experiment
• Data Collection, Tabulation & Processing
- tables are usually drawn vertically
- we draw graphs as they average out our results (note: there's no need to begin the graph at "0". Also, a best fit line should be drawn, with the same number of points on each side)
- scientific drawings (note: label, scale, accuracy)
• Interpretation of Results (Data Analysis)
• Limitations (due to them there might have been a decrease in the accuracy of the results)
-
Subscribe to:
Posts (Atom)