Lab #1: Law of Conservation of MassName:

PROCEDUREPeriod:

Date:

Purpose: To attempt to verify & observe the Law of Conservation of Mass - In any chemical reaction, the total

mass of the reactants is always equal to the mass of the products.

Materials:

  • balance
  • beaker
  • 1 balloon w/baking soda
  • ~15 g baking soda
  • ~50 mL vinegar
  • 100 mL graduated cylinder

Pre–Lab Questions/Hypothesis:

1. What happens when you combine baking soda and vinegar?

2. What does “to conserve” mean?

3. What is the Law of Conservation of Mass?

Introduction: The word equation for the following reaction is as follows:

vinegar + baking soda sodium acetate + water + carbon dioxide

The chemical equation for the reaction is:

CH3COOH + NaHCO3NaC2H3O2 + H2O + CO2

Procedure:

  1. Come get your cup with 40mL of vinegar
  2. Pour the 40mL of vinegar from the cup into the graduated cylinder
  3. Take the mass of the graduated cylinder with the vinegarAND the mass the balloon w/baking sodaTOGETHER using the scale. Record the mass in the data table as the INITIAL MASS.
  4. Fit the balloon onto the graduated cylinder making sure NO baking soda spills into the cylinder
  5. Once the balloon is on the flask, lift the balloon so the baking soda mixes with the vinegar (see image below). Write your observations on your data sheet.
  6. Once the reaction stops, make sure your scale reads zeroand take your ENTIRE setup and place it on the scale. Record the mass in the data table as the FINAL MASS.
  7. Clean-up your station and begin answering the conclusion section.

Lab #1: Law of Conservation of MassName:

DATA AND RESULTSPeriod:

Date:

Purpose: To attempt to verify & observe the Law of Conservation of Mass - In any chemical reaction, the total

mass of the reactants is always equal to the mass of the products.

Data Table

Initial Mass
(Cylinder + Balloon = Total) / Cylinder & Vinegar / Balloon & Baking Soda / Total
Observations of Reaction
Final Mass
Error (Final mass – Initial (Total) mass)
(only if the Final mass is NOT = to Starting mass)

Show work for calculation of ERROR Below if needed:

ANSWER:

Inquiry/Analysis Questions:

Please phrase the question in the answer.

  1. What evidence was there that a chemical reaction occurred? (please reference any/all of the 5 evidence indicators!)
  1. How did the final mass compare with the initial mass? If the law of conservation of mass was violated, (not eaqual) list some reasons why.
  1. Indicate the state of matter for each reactant(baking soda and vinegar) and product (sodium acetate, water, and carbon dioxide).
  1. What are some ways in which this experiment could be improved? (at least 2 ways!)