ChemistryName: ______

Ms. BoonPeriod: _____ Date: _____

CONSERVATION BLOWS IT UP

INTRODUCTION AND PURPOSE:

In a chemical reaction, one or more substances change into one or more new substances with different chemical and physical properties. The identity of the products differs from the identity of the reactants. However, the amount of matterdoes not change. The amount of matter is characterized by mass. We measure mass in grams using a balance.

Because gases are often products of chemical reactions, one might think that matter is lost as a result of a chemical reaction. But, if we take the time to capture the gaseous product, we will see that the mass of the products equals the mass of the reactants. In this laboratory experiment, you will react baking soda with vinegar to determine if matter really is conserved.

PRE-LABORATORY QUESTIONS: Use page 260-266 to answer the following questions.

Write the word equation for the reaction of baking soda and vinegar.
Write the chemical reaction equation for the reaction of baking soda and vinegar. Label the reactants and products. Include signs showing the states of matter.
Hypothesis: According to the law of conservation of mass, the mass of the reactants will be (choose one: the same, more, less) than the mass of the products.

SAFETY PRECAUTIONS

Safety goggles must be worn at all times during this experiment. Wash hands following experiment. Do not rub eyes.

MATERIALS

ChemistryName: ______

Ms. BoonPeriod: _____ Date: _____

· vinegar

· baking soda

· 1 plastic bottle

· 1 graduated cylinder

· 1 balloon

· 1 piece of weighing paper

· 1 balance

ChemistryName: ______

Ms. BoonPeriod: _____ Date: _____

PROCEDURE

REACTION 1

  1. Measure with a graduated cylinder 50 mL of vinegar into the bottom of a water bottle.
  2. Measure 5 grams of baking soda on the weigh paper with the balance.
  3. Place the water bottle and the weigh paper on the balance at the same time. Record the mass in the data table as the “before” mass for reaction 1.
  4. Remove the items from the balance.
  5. Pour the baking soda into the bottle with the vinegar. Record observations in Data Table 1.
  6. After the reaction is complete, place the bottle and empty weigh paper on the triple beam balance. Record the mass as the “after” mass for reaction 1.
  7. Pour the contents of the bottle down the sink and rinse out the bottle.

REACTION 2

  1. Measure with a graduated cylinder 50 mL of vinegar into the bottom of a water bottle.
  2. Measure 5 grams of baking soda on the weigh paper with the balance.
  3. Pour the baking soda into the balloon.
  4. Stretch the opening of the balloon over the opening of the bottle. Do not dump the baking soda into the vinegar yet.
  5. Place the bottle with the attached balloon on the balance. Record the mass in your data table as the “before” mass for reaction 2.
  6. Remove the items from the triple beam balance.
  7. Dump the contents from the balloon into the Erlenmeyer flask. Record yourobservations in the data table.
  8. After the reaction is complete, place the Erlenmeyer flask with the balloon still inflated on the triple beam balance and record the mass as the “after” mass for reaction 2.

DATA TABLE #1

Description (observations) / Initial Mass (g)
“before” / Final Mass (g)
“after” / Change in Mass (g) / Was Mass Conserved?
Reaction 1
Reaction 2

DATA ANALYSIS AND CALCULATIONS

  1. Solve for the change in mass of each reaction and record answers in the Data Table. (Hint: Subtract final mass minus initial mass to find the change in mass.)
  2. Based on your calculations of the change in mass, determine whether mass was conserved or not. Record your answer in the Data Table. (Hint: Conserved means “stayed the same.”)

LAB REPORT. Write a three-paragraph lab conclusion on a separate sheet of paper. Imagine that the reader is a student who was absent and who needs to understand what you did, how you did it, and why you did it. Use the outline below.

Outline / Brainstorming: Write notes here before you begin writing.
Paragraph 1: Purpose, materials, and procedure.
  • What was the purpose of the lab? What were you trying to find out?
  • Explain the lab procedure and the materials used.
  • What were the safety concerns?
  • Did you lab group change or modify the procedure in any way?

Paragraph 2: Data Collection
  • Describe the chemical reaction that you performed in the lab. What were the reactants and products?
  • Describe your data from reaction 1. What was the initial mass and final mass? How did you calculate the change in mass? What was the change in mass?
  • Describe your data from reaction 2. What was the initial mass and final mass? How did you calculate the change in mass? What was the change in mass?

Paragraph 3: Data Analysis and Conclusions
  • Compare your results from reaction 1 and 2. How are they similar? How are they different? Why?
  • Were these the results that you expected? Why or why not?
  • Use your lab results to explain the law of conservation of mass.

CONSERVATION BLOWS IT UP: PRE-LABORATORY ASSIGNMENT

In our next Chemistry class, you will conduct an experiment involving the chemical reaction of baking soda and vinegar. To prepare for the lab, complete the following assignment. This is a graded portion of your lab report.

Read pp. 260-266 in your textbook and then answer the following questions on a separate sheet of paper.

  1. What is a chemical reaction?
  2. Describe evidence that chemical reactions take place during a fireworks display. (Use Table 1 on pp. 261 for hints.)
  3. What is a chemical equation?
  4. What is the chemical name for baking soda? (See pp. 264-265.)
  5. What is the chemical name for vinegar? (See pp. 264-265.)
  6. Write the chemical equation for the reaction of baking soda and vinegar in words.
  7. Write the chemical equation for the reaction of baking soda and vinegar using the chemical formulas. (See pp. 264-265.)
  8. What are the reactants? What are the products?
  9. The molar mass is the mass of one mole of a substance. Use your periodic table to calculate the molar mass of each reactant and each product. (Refer to pp. 237-239 or your class notes on molar mass.)

ChemistryName: ______

Ms. BoonPeriod: ______Date: ______

CONSERVATION BLOWS IT UP: PRE-LABORATORY ASSIGNMENT

In our next Chemistry class, you will conduct an experiment involving the chemical reaction of baking soda and vinegar. To prepare for the lab, complete the following assignment. This is a graded portion of your lab report.

Read pp. 260-266 in your textbook and then answer the following questions on a separate sheet of paper.

  1. What is a chemical reaction?
  2. Describe evidence that chemical reactions take place during a fireworks display. (Use Table 1 on pp. 261 for hints.)
  3. What is a chemical equation?
  4. What is the chemical name for baking soda? (See pp. 264-265.)
  5. What is the chemical name for vinegar? (See pp. 264-265.)
  6. Write the chemical equation for the reaction of baking soda and vinegar in words.
  7. Write the chemical equation for the reaction of baking soda and vinegar using the chemical formulas. (See pp. 264-265.)
  8. What are the reactants? What are the products?
  9. The molar mass is the mass of one mole of a substance. Use your periodic table to calculate the molar mass of each reactant and each product. (Refer to pp. 237-239 or your class notes on molar mass.)

ChemistryName: ______

Ms. BoonPeriod: ______Date: ______

CONSERVATION BLOWS IT UP: PRE-LABORATORY ASSIGNMENT

In our next Chemistry class, you will conduct an experiment involving the chemical reaction of baking soda and vinegar. To prepare for the lab, complete the following assignment. This is a graded portion of your lab report.

Read pp. 260-266 in your textbook and then answer the following questions on a separate sheet of paper.

  1. What is a chemical reaction?
  2. Describe evidence that chemical reactions take place during a fireworks display. (Use Table 1 on pp. 261 for hints.)
  3. What is a chemical equation?
  4. What is the chemical name for baking soda? (See pp. 264-265.)
  5. What is the chemical name for vinegar? (See pp. 264-265.)
  6. Write the chemical equation for the reaction of baking soda and vinegar in words.
  7. Write the chemical equation for the reaction of baking soda and vinegar using the chemical formulas. (See pp. 264-265.)
  8. What are the reactants? What are the products?
  9. The molar mass is the mass of one mole of a substance. Use your periodic table to calculate the molar mass of each reactant and each product. (Refer to pp. 237-239 or your class notes on molar mass.)

CONSERVATION BLOWS IT UP: PRE-LABORATORY ASSIGNMENT -- Answers

In our next Chemistry class, you will conduct an experiment involving the chemical reaction of baking soda and vinegar. To prepare for the lab, complete the following assignment. This is a graded portion of your lab report.

Read pp. 260-266 in your textbook and then answer the following questions on a separate sheet of paper.

  1. What is a chemical reaction? (answer on pp. 260)
  • A chemical reaction is the process by which one or more substances change into one or more new substances whose chemical properties and physical properties differ from those of the original substances.
  • In a chemical reaction, the original substances, which can be elements or compounds, are known as reactants. The substances created are called products.
  1. Describe evidence that chemical reactions take place during a fireworks display. (Use Table 1 on pp. 261 for hints.)
  • Some evidence of chemical reactions during a fireworks display are the production of light and sound. Also, there is an explosion which would likely release heat. That is why fireworks are dangerous. Additionally, fireworks come in many colors and the change in color can be evidence of a chemical reaction.
  1. What is a chemical equation? (answer on pp. 263)
  • A chemical equation shows the chemical formulas and relative amounts of all the reactants and products that are part of a certain chemical reaction. The reactants are on the left, then there is an arrow in the middle, and the products are on the right. The arrow means “forms” or “produces”.
  1. What is the chemical name for baking soda? (See pp. 264-265.)
  • Sodium hydrogen bicarbonate
  1. What is the chemical name for vinegar? (See pp. 264-265.)
  • Acetic acid (dissolved in water)
  1. Write the chemical equation for the reaction of baking soda and vinegar in words.

Baking soda (sodium hydrogen bicarbonate) + vinegar (acetic acid)  sodium acetate + carbon dioxide + water

  1. Write the chemical equation for the reaction of baking soda and vinegar using the chemical formulas. (See pp. 264-265.)

NaHCO3 (s) + HC2H3O2 (aq) NaC2H3O2 (aq) + CO2 (g) + H2O (l)

  1. What are the reactants? What are the products?

Reactants -- NaHCO3 (s) + HC2H3O2 (aq)

Products -- NaC2H3O2 (aq) + CO2 (g) + H2O (l)

  1. The molar mass is the mass of one mole of a substance. Use your periodic table to calculate the molar mass of each reactant and each product. (Refer to pp. 237-239 or your class notes on molar mass.)

Reactants: NaHCO3 = 84.01 g/molHC2H3O2 = 60.06 g/mol

Products: NaC2H3O2 = 82.04 g/mol & CO2 = 44.01 g/mol & H2O = 18.01 g/mol