Try this science investigation at home to challenge the law of conservation of mass.
Structure and features
Materials you'll need for this science investigation:
- safety goggles
- a balloon
- a funnel
- baking soda (sodium bicarbonate)
- a teaspoon
- vinegar (standard 5% acetic acid)
- a flask or bottle
- a measuring cup
- a balance scale that reads to at least 0.1 gram
- optional: extra materials to experiment with, such as more balloons, zip-seal sandwich bags, 2-litre plastic bottles, etc.
Follow the instructions on the webpage and answer these questions:
- What happened to the shape of the balloon? Draw a diagram to show the change and and annotate to explain why this occurred.
- What was the weight:
- before adding baking soda?
- when the baking soda was first added?
- at the completion of the chemical reaction?
3. Can you explain why the mass stayed the same but the weight changed?
Read the explanation provided then try the quiz attached.
Teacher notes
- Science inquiry skills strand and science understand strand
- Chemical sciences
- Year 9
- Law of conservation of mass.
Students learn during a chemical reaction that mass isn't created or destroyed through this science investigation.
Students may still have a misconception between the difference of mass and weight.
