Does more vinegar blow a balloon up bigger?
- 🎈 Balloons
- 🥽 Goggles on
- 🧽 A bit messy
My hypothesis
If I change how much vinegar goes in the bottle, then how far around the balloon is will ______, because ______.
You fill in the blanks. Think about what the gas is made from, and whether the vinegar can keep making it for ever. A guess is a good because: the test finds out.
Change, measure, keep the same
CHANGE
how much vinegar goes in the bottle: A quarter cup, Half a cup, 1 cup
MEASURE
how far around the balloon is, in cm
KEEP THE SAME
- 2 teaspoons of baking soda every time
- balloons of the same kind, stretched the same way
- the same bottle
- measuring around the widest part
Scientists call the thing you change the independent variable and the thing you measure the dependent variable. The things you keep the same are the controls: if one of them changed too, you wouldn't know which change made the difference. Try each of the 3 levels 3 times.
What you need
- A balloon: 9, the same kind
- Baking soda
- White vinegar: about 2 cups
- An empty plastic bottle: 1, the same one each time
- A kitchen funnel
- A measuring cup
- Measuring spoons
- String or yarn
- A tape measure, or a long ruler
- ✂️ Kid scissors
Steps
- Put your goggles on.
- Grown-up: A grown-up stretches nine balloons by blowing each one up once and letting the air out.
- Use the funnel to put 2 teaspoons of baking soda into a balloon.
- Pour a quarter cup of vinegar into the bottle.
- Stretch the neck of the balloon over the bottle's mouth, keeping the baking soda in the balloon.
- Lift the balloon up so the baking soda falls into the vinegar, and wait for the fizzing to stop.
- Cut a piece of string and wrap it around the widest part of the balloon.
- Lay the string along the tape measure, and write the length in your table.
- Rinse the bottle and repeat with new balloons: three tries each for a quarter cup, half a cup and 1 cup.
- Find the mean for each amount, and draw a line graph with vinegar along the bottom.
One step is a grown-up's, marked above. Write each number down straight away, in the table below, so nothing is lost.
Your results table
Name ______________________ Fair day ____________
Question: Does more vinegar blow a balloon up bigger?
I changed: Vinegar I measured: how far around the balloon is (cm)
| Vinegar | Try 1 (cm) | Try 2 (cm) | Try 3 (cm) | Mean |
|---|---|---|---|---|
| A quarter cup | ||||
| Half a cup | ||||
| 1 cup |
MY GRAPH (a line graph: vinegar along the bottom, cm up the side)
What I noticed: ______________________________________________
From 4th grade, add the tries for each level and divide by how many there were: that's the mean, and it goes in the last column. Then draw a line graph, because the thing you change is a number that goes up.
Name ______________________ Fair day ____________
Question: Does more vinegar blow a balloon up bigger?
If I change how much vinegar goes in the bottle, then how far around the balloon is will ________________, because _____________________________________________
| I CHANGE | I MEASURE | I KEEP THE SAME |
|---|---|---|
| Vinegar: A quarter cup, Half a cup, 1 cup | how far around the balloon is (cm) |
|
What I think will happen, in my own words:
Name ______________________ Fair day ____________
Question: Does more vinegar blow a balloon up bigger?
| Date | What I did | What I saw | What I think |
|---|---|---|---|
Name ______________________ Fair day ____________
Question: Does more vinegar blow a balloon up bigger?
| Date | What I did | What I saw | What I think |
|---|---|---|---|
Name ______________________ Fair day ____________
Question: Does more vinegar blow a balloon up bigger?
| Date | What I did | What I saw | What I think |
|---|---|---|---|
Name ______________________ Fair day ____________
Question: Does more vinegar blow a balloon up bigger?
My hypothesis was ☐ right ☐ partly right ☐ not right.
I know because my numbers show:
What surprised me, or what might have gone wrong (7th and up):
Next time I would test:
Idea: Change a second thing: keep half a cup of vinegar and try 1, 2 and 3 teaspoons of baking soda, and graph both lines together.
Why it works
Baking soda and vinegar react and make a gas called carbon dioxide, and the gas fills the balloon. More vinegar can make more gas, up to a point. Once all the baking soda is used up, extra vinegar has nothing left to react with, so the balloon stops getting bigger.
Going further (7th and up): Change a second thing: keep half a cup of vinegar and try 1, 2 and 3 teaspoons of baking soda, and graph both lines together.
Board layout
- ❓ Question (10 × 8 in): Does more vinegar blow a balloon up bigger?
- 💭 Hypothesis (10 × 9 in): If I change how much vinegar goes in the bottle, then how far around the balloon is will ______, because ______.
- 🧺 Materials (10 × 12 in): 9 things: see your list.
- 🪜 Steps (22 × 9 in): 10 steps, three tries at each level.
- 📊 Results (22 × 16 in): Your table (Vinegar down the side, tries across) and your line graph.
- ✅ Conclusion (10 × 14 in): My hypothesis was right / partly right / not right. I know because…
Materials to list: A balloon; Baking soda; White vinegar; An empty plastic bottle; A kitchen funnel; A measuring cup; Measuring spoons; String or yarn; A tape measure, or a long ruler.
Bring photos or drawings of your test. Nothing wet, hot, powered or alive on the table.
This project at your grade
| 1st–3rd grade | Tries: three at each level (one is fine at a first fair). The table: levels and tries, numbers or pictures. The graph: a picture, or a simple bar graph. The conclusion: what happened, in their words. |
|---|---|
| 4th–6th grade | Tries: three at each level. The table: units in the header and a mean column. The graph: a bar graph, or a line for a number that grows. The conclusion: right, partly or not, and the numbers that show it. |
| 7th grade and up | Tries: three or more at each level. The table: a mean for every level of both tests. The graph: a graph with two lines or two sets of bars. The conclusion: the numbers, what might have gone wrong, and a next question. Second variable: keep half a cup of vinegar and try 1, 2 and 3 teaspoons of baking soda, and graph both lines together. |
From 4th grade up, the table gets a mean column. See every project for 3rd grade, or print a blank results table.
What a judge will ask
- What did you change, and what did you measure? I changed how much vinegar goes in the bottle and measured how far around the balloon is, in cm.
- What did you keep the same, and why does that matter? I kept 2 teaspoons of baking soda every time and balloons of the same kind, stretched the same way the same, so the only difference was how much vinegar goes in the bottle.
- How many times did you test it? 3 times at each of my 3 levels.
- If you did it again, what would you change or test next? I'd keep half a cup of vinegar and try 1, 2 and 3 teaspoons of baking soda, and graph both lines together.
Make it yours
Keep this project on this device and Peabody counts down to your fair day, with a plan for each day. Nothing is sent anywhere.
Try next
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