Question

Design an experiment that will compare two different factors that may affect the rate of the Alka-Seltzer reaction. Possible factors to be investigated include temperature, surface area, agitation, and amount of reactants.

Answer 1

We need to analyze the two factors independently, as to avoid the need for statistical analysis.

I might recommend using temperature and amount of reactants as the factors, as they are the easiest to quantify.

First, perform a control run. Let's say 1 alka-seltzer tablet in 8 oz of water at standard temperature (25 C). Recording the time it takes to completely dissolve.

Second, vary one and only one factor, as to isolate it. Let's say temperature here. Heat the water to some elevated temperature, drop in 1 tablet and record the time it takes to dissolve.

Third, vary the other factor, which is amount of reactants. If we do 2 tablets in 16 oz of water, we aren't changing the proportions. Therefore, do 2 tablets in 8 oz of water or 1 tablet in 16 oz of water. Again, record the time. Ensure that the water is close to 25 C.

Finally, compare times and draw conclusions.