Rates of Reaction Lab - Concentration
Name: _________________________________________ Date: ___________
Purpose: To determine how concentration affects the rate of a chemical reaction
Materials: 100 ml graduated cylinder, 10 ml graduated cylinder, 100 ml beaker, 0.2M Na2S2O3, 3M HCl, water, stopwatch
1. You will be completing 5 trials using the amounts in the table below. For each trial:
Trial 1 2 3 4 5
Na2S2O3 10 ml 20 ml 30 ml 40 ml 50 ml
Water 40 ml 30 ml 20 ml 10 ml 0 ml
a. Use your 100 ml graduated cylinder to measure and add Na2S2O3 (aq), and H2O to the 100 ml beaker.
b. Place the beaker on the X at the bottom of this paper. You are going to look through the beaker at the X and time how long it takes the X to not be visible.
c. Use your 10 ml graduated cylinder to measure out 5ml of HCl and add it to the beaker. As you add it, start your stopwatch.
d. Stop your stopwatch when you can no longer see the X through the beaker, and record the time in the data table below.
2. Rinse the beaker out and repeat for each trial.
3. Dispose of all liquids in the sink, rinse out all beakers and graduated cylinders with water and return them to where they came from.
Trial 1 2 3 4 5
1. The reaction that you performed was aqueous hydrochloric acid + aqueous sodium thiosulfate aqueous sodium chloride + gaseous sulfur dioxide + solid sulfur + liquid water. Write out the balanced equation for the reaction.
2. Which one of the products is the precipitate? _____________________
3. What will happen to the number of particles in a given volume if the concentration increases?
4. How would this increase in the number of particles affect the rate of reaction?
5. Construct a graph of time versus the volume of Na2S2O3 for each beaker on a piece of graph paper, using your data and staple it to this lab.
a. Describe the relationship between the concentration of Na2S2O3 and the...