AlgebraLab

Visualizing a Graph: Concentration vs Height

By G Waller

Purpose: To examine the relationship between the concentration of a reactant and the amount of gaseous product generated.

Time Required: One 50 minute class period

Group Size: 6 students

Materials:

  • 5 100 mL graduated cylinders
  • Vinegar
  • Water
  • Baking soda
  • Pipet
  • Dish soap
  • Set of measuring spoons
  • Syringe


Prior Knowledge:Reaction rates

Procedure:

  1. You will set up a series of five graduated cylinders that contain a set of diminishing concentrations of vinegar.

    1. Using a syringe, measure out 10.0 mL of vinegar and put it into a 100.0 mL graduated cylinder.


    2. Using the syringe, draw up 8 mL of vinegar + 2 mL of water, to make a total of 10.0 mL of solution. Place in the second graduated cylinder.


    3. Using the syringe, draw 6 mL of vinegar + 4 mL of water, to make a total of 10.0 mL of solution. Place in the third graduated cylinder.


    4. Using the syringe, draw 4 mL of vinegar + 6 mL of water, to make a total of 10.0 mL of solution. Place in the third graduated cylinder.


    5. Using the syringe, draw 2 mL of vinegar + 8 mL of water, to make a total of 10.0 mL of solution. Place in the third graduated cylinder.


    6. Add one drop of dish soap to each graduated cylinder.


  2. Now you need to measure out 5 piles of baking powder that will be mixed with the vinegar.

    • Measure out 1/2 teaspoon of baking soda onto 5 separate small pieces of paper.


  3. Now it’s time to mix the reagents together!!! You are looking to measure the height of the soap bubbles as they rise up the graduated cylinder column.

    1. Mix 1/2 teaspoon of baking soda with the 10.0 mL of vinegar in the first graduated cylinder. Record the greatest height of the bubbles.


    2. Repeat with each of the of the graduated cylinders, recording the greatest height of the bubbles each time.


Data Table:

Baking soda+Vinegarsodium acetate+water+Carbon dioxide gas
NaHCO3+HC2H3O2NaC2H3O2+H2O+CO2


 height (in mL)
graduated cylinder #1
10.0 mL vinegar		 
graduated cylinder #2
8.0 mL vinegar + 2 mL H2O		 
graduated cylinder #3
6.0 mL vinegar + 4 mL H2O		 
graduated cylinder #4
4.0 mL vinegar + 6 mL H2O		 
graduated cylinder #5
2.0 mL vinegar + 8 mL H2O		 
Calculations:

  1. Make of graph of your experimental data . Use volume of vinegar added to baking soda as the independent variable and height as the dependent variable.


  2. Construct a line of best fit and calculate the slope of the line.


  3. Write the equation for the line