Experiment on reaction tempo - Help!

[Janika]

How does the size of the area of the reaction tempo influences the reaction tempo?

[deleted-71487]

This is a very difficult question to answer as you have asked it. Various chemical reactions change differently with "area" (do you mean surface area or volume?)?

Do you have a specific science fair project in mind?

[Janika]

This is a very difficult question to answer as you have asked it. Various chemical reactions change differently with "area" (do you mean surface area or volume?)?

Do you have a specific science fair project in mind?

Hi Ray.

Sorry for the confusion. I meant the surface area. Yes the specific experiment we would like to use is by dissolving one whole"Rennie" (Here in South Africa it's an "alkaline" you drink when you have indigestion/heartburn, which then neutralises the acid in your stomach.) in vinegar, we then measure how much gas it sets free. The second time we want to dissolve a crushed "Rennie" (which automatically expands the surface area) in vinegar and then measure again how much gas it sets free. (the gas thus will form quicker) And thereby define how the surface area influence the reaction tempo.

I need some help please on the planning, method of the experiment and accurately discussing the results. (drawing up graphs, etc)

[deleted-71712]

Janika,

A few suggestions for you...

1. Measuring a gas coming out of a liquid: For experiments on soda losing carbonation, we've had students either attach balloons to the top of a bottle or attach a tube to the bottle and connect it to a measuring cup upside-down in a pan of water. The second method is more precise because you can read the volume of water displaced by the accumulating gas, and you don't have to worry about differences in the stretchiness of different balloons. Since you're interested in the rate of the reaction, you would want to measure the gas volume produced at many times during the reaction, not just the total volume produced. (The total volume of gas should always be the same if you're reacting the same size pill in an excess of acid, it will just be produced faster if the pill has a larger surface area.)

https://www.sciencebuddies.org/science- ... 46&p=19811

2. Plots: You will ultimately want to make a plot with your dependent variable (reaction rate) on the vertical axis and your independent variable (surface area) on the horizontal axis. I absolutely think that you should do a pill crushed into a powder as a limiting case, but the problem is that you won't have a numerical value for the surface area. If you also do pills sliced into different numbers of pieces, then you can calculate their exact surface areas from the geometry of the pieces.

3. I'm not familiar with Rennies, but many pills have some kind of coating on the outside. That could make interpreting your results rather complicated, so if you can find a pill with no external coating, that would be best.

Amanda

[Janika]

Hallo Amanda

Thank you so much! You surely helped a great deal!!
Rennies luckily doesn't have any kind of coating, it is comparable to an effervescent tablet.
I agree with you on the second method of the experiment, seeing that we need those measurements in our sum of the reaction tempo. Do you maybe have any suggestions on how one could do the sum and show it on the bar graph?

Kind regards

Janika