Early Work: March 2nd
1. Please grab a computer and go to
my school district website.
2. Take out your hypothesis,
procedure, and data from the
vinegar and baking soda lab we did
last class.
Chemical reaction
CH3COOH + NaHCO3
Acetic Acid and Sodium Bicarbonate
CH3COONa + H2O + CO2
Sodium Acetate and Water and Carbon Dioxide
•Does the total mass of the matter
involved in the reaction change?
•Can matter be created or destroyed
during a chemical reaction?
Agenda: March 2nd
• Baking soda and vinegar reaction in depth
• Check crystal formation project
• Revise MSP practice
• Jordan and Isaiah watch a chemical reaction
between baking soda (NaHCO3) and vinegar
(CH3COOH).
• They noticed that combining the two reactants
produced bubbles and they guessed that it was a
gas being produced in the reaction.
• They wondered if there was a relationship
between the amount of baking soda and vinegar
and the amount of gas produced in the reaction.
• Write a testable question based on their
observations.
• Jordan and Isaiah decided to investigate the
following question:
• What is the perfect ratio of volumes of baking
soda and vinegar that will fill a ziplock bag to
capacity without bursting the bag open?
• What would be the variable you might use in
the lab?
• Discuss with a neighbor your hypothesis based
on the question above.
• Write a hypothesis and procedure and carry out the
experiment.
• Materials:
– Ziplock bag (needs to cleaned after every trial)
– Baking soda
– Vinegar
– Graduated cylinder
– Scale
– Measuring scoop
– Pipette
– Paper towels
• Be sure to record data in your cornell notes.
• Once you have collected data, write a conclusion.
Amount vinegar
Amount Baking soda
Result (burst, did not inflate)
100 ml
100
100ml
100
100
100ml
100ml
100 ml
100 ml
100 ml
40ml
60ml
70ml
100ml
40ml
50ml
60ml
50ml
70ml
85
80
80
50 ml
60 Ml
90 Ml
100 Ml
7.5 grams
8 grams
8.5 grams
9 grams
6 grams
20 grams
5grams
15 grams
6 grams
3.8 grams
7grams
10grams
20grams
42grams
12.9g
22.9g
32.9gr
3grams
10grams
30g
30
30
10 Grams
40 Grams
60 Grams
100 Grams
inflated
Burst
Burst
Burst
Inflated, not pop
P0PPED !
Inflated!! :D
Inflated
Inflated:D
Inflated
All inflated. Almost burst
1.3 gas was product
1.6 gas product
popped
inflated
Inflated
Inflated
1
Same
Exploded
4grams
1 gram
0.5 G
0.6 G
0.8 G
POPPED ! O:
Write a conclusion
• Write a conclusion in the summary of your cornell
notes.
– Answer the testable question: What is the perfect ratio
of volumes of baking soda and vinegar that will fill a
ziplock bag to capacity without bursting the bag open?
– Use supporting data.
– Make a mathematical comparison.
– Connect experiment to real world scenario.
• Go to Mr. Baur’s website and write final drafts of
hypothesis, procedure, and conclusion.
Select a chemical, find a partner, get a
computer.
•
•
•
•
•
•
•
Alum: AlKSO4
Borax: NaBO7
Table salt: NaCl
Copper sulfate: CuSO4
Sugar (sucrose): C12H22O11
Epsom salts: MgSO4
Baking soda: sodium bicarbonate: CHNaO3
Crystal chemical research
• Common name and chemical formula
• Common uses
• Density
• Melting and boiling pts
• Solubility in water at 20 oC
• Color
• 3-D Arrangement of compound
• Safety concerns
http://webmineral.com/
http://www.chemspider.com/
Procedure
1. On a piece of tape, label a glass dish with the name of the
chemical you will be using.
2. Pour 200 mL of hot water (80 degrees Celsius) into the dish.
3. Weigh 50 grams of chemical into a plastic cup.
4. Add chemical to hot water until dissolved. Stir until
dissolved.
5. Find the mass of the remaining chemical in the plastic cup
and subtract it from 50 grams to find the amount of
chemical you added. Tell this number to Mr. Baur.
6. Wrap a pipe cleaner or string around a pencil and place it on
the top of the dish.
7. Crystals should form in the next few days as the water
evaporates.