Part B
Next, you’ll test your hypothesis from part A by examining the reaction times of vinegar and baking soda in water at four different temperatures. You’ll carry out the reaction using water at room temperature (about 25°C), 40°C, 60°C, and 80°C. Make sure that you use the same amounts of vinegar and baking soda for all three three trials.
Gather all the materials, and perform these steps for each trial:
Heat at least cup (60 milliliters) of water to the required temperature (refer to the data table). Water may be heated on a stove, on a hot plate, or in a microwave oven.
Measure and record the actual temperature of the water.
Measure 1 tablespoon (15 milliliters) of the water into the cup.
Add teaspoon (1.5 grams) baking soda to the water, and stir until it is dissolved. The solution will be clear.
Measure 1 tablespoon (15 milliliters) of vinegar, but do not pour it into the cup yet.
Very quickly, do all of the following:
a. Pour the measured vinegar into the cup.
b. Start the stopwatch.
c. Stir or carefully swirl the substances in the cup.
The chemical reaction will produce bubbles. You’ll be able to see the bubbles and hear them pop. Watch and listen for when the reaction stops. When it looks and sounds like it has finished, stop the stopwatch.
Record the reaction time in the data table.
Discard the solution down the drain, and rinse the cup.
Repeat steps 1–9 of this procedure, doing three trials for each water temperature. Record the average temperature and reaction time for each set of the three trials. Read this math review to know how to calculate average of a data set.