The objective of this experiment is to determine the identity of our unknown solution. In order to do this, Courtney conducts three trials. Each trial is done by mixing sodium hypochlorite and the unknown solution in one of three stoichiometric ratios, 1 to 1, 3 to 1, or 4 to 1. The chemical whose ratio yields the greatest change in temperature will be considered our unknown solution. Watch as Courtney demonstrates two of these three trials. Alright, so this is for experiment two.
We are doing our first run to figure out what our unknown is. So we started out with 2.5 milliliters of the unknown in here and we're going to add 7.5 milliliters of the bleach because this is one of the ideal stoichiometric ratios. And then we'll just push start and see how much the temperature changes.
I'm starting out with 8 milliliters of the bleach solution and 2 milliliters of my unknown because that's one of the storage metric ratios that could give me the highest temperature change. And I'm just going to press start on here. I already have the bleach in here and I'm just going to add in my unknown.
So you can see the temperature is starting to rise. And then we'll just keep track of what the highest temperature it gets to is so that we can subtract it from the initial temperature. Here are the results from the three trials Courtney performed.
In order to confirm the identity of the unknown solution, Courtney has done eight more trials. These trials were done just as before, except four of these trials were chosen in ratios above the suspected ratio, while four of them were done below the suspected ratio. Make sure to copy this data onto your own report form. Then, download the calculation guide for this experiment on Learning Suite and use this data to make a graph of the results.
If you're unfamiliar with graphing software like Excel, search for the Experiment 2 Calculations video. on Rebecca Sansom's YouTube channel. After creating the graph, you'll be ready to finish the report.