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...

	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!