IPS Lab 1.1 – Heating Baking Soda
Name________________________
Block ________________________
We will be heating baking soda (sodium bicarbonate, NaHCO3) to see what happens. This is an exercise in
observation, formulating testable questions, and coming up with good scientific explanations.
I. INITIAL OBSERVATIONS
Describe the baking soda in as much detail as you can. You must have 5 distinct observations. Identify each
observation as quantitative or qualitative. (5 pts)
1
2
3
4
5
II. TESTABLE QUESTION
Based on your initial observations, formulate a testable question. In other words, what do you think will
happen to the sample when we heat it up? (2 pts)
III. FURTHER OBSERVATIONS
Now set up your own apparatus as demonstrated and shown in Fig 1.1 on page 2 of the IPS textbook. Once you
have built it, read the numbered directions that follow this paragraph. When you have an understanding of what
you are to do, call me over to inspect your apparatus. If it passes inspection, I will light your alcohol burner.
(1 pt each × 4)
1. The flame will heat the baking soda in the test tube.
2. Watch the whole apparatus carefully for any changes.
a. What happens inside the test tube?___________________________________________
b. What happens inside the inverted bottle?__________________________________
3. When it appears that no further changes are taking place, pull the rubber tube completely out of the
water while the flame is still on. After the tube is removed, blow out the flame.
a. From where did the gas come?__________________________________________________
b. From where did the droplets on the test tube come?_____________________________
Now describe the baking soda in the test tube. Does it have any qualities that are different from your initial
observations? If so, list them here. (1 pt) ______________________________________________
Do you believe that the sample of baking soda is unchanged? Why or why not? (2 pts)
Let’s find out if the sample that was heated is really unchanged. We will do this by comparing it with a fresh
sample of baking soda. Get another test tube that contains about the same amount of baking soda. Make sure
that you keep track of which test tube is which. Fill both test tubes about ¼ of the way full with tea. Observe
the mixture in each test tube. Do they appear the same? Describe the difference if there is one. (1 pt)
___________________________________________________________________________
IV: SCIENTIFIC EXPLANATION
Can you claim that the original sample has changed in some way? _________________________________
Write a scientific explanation that validates your claim. What evidence leads you to believe that the original
sample has changed? (Remember – your evidence must be sufficient and appropriate.) Explain the reasoning
that links your claim to your evidence. (5 pts)
For example: Based on (insert your evidence), I conclude that (insert your claim) because (insert your reasoning).