Students are introduced to the concepts of chemical change and physical change in elementary school. These concepts are covered in greater detail as students progress through middle school and high school.
A chemical change occurs when substances combine (the reactants) to form new substances (the products) as atoms are rearranged. Common evidences of a chemical change include a change of color, odor, temperature, the formation of a gas, or a precipitate A physical change occurs when there is a change in physical properties of a substance but not chemical compostion.
Common physical changes include melting, change of size, volume, color, density, and crystal form. The classic baking soda and vinegar reaction provides evidence of a chemical change due to the formation of a gas and a temperature change. Students tactually experience the formation of a gas as carbon dioxide fills up the balloon and sense a change of temperature.
Related Vocabulary:
As students complete this activity they will immediately notice the production of the gas. However, it may be necessary to ask the students to observe the temperature of the substance in the bottle after the reaction. It will be colder than before.
Please see the activity at https://www.perkins.org/resource/conservation-mass/ for a similar experiment with a focus on Conservation of Mass
Please note that this worksheet for the lab is available to be downloaded in regular print, large print, and Duxbury (contracted and uncontracted braille) at the bottom of this page under “Attached Files”.
Name: _____________ Class: ______________
Lab: Baking Soda and Vinegar
Problem: What will happen if I mix vinegar and baking soda? Is it a chemical change or a physical change?
Hypothesis: _______________________________
Procedure:
Results: __________________________________
Conclusion: ______________________________
Latex Free option: This activity was recently chosen by a student of mine as the basis for her science project. However, she is highly latex allergic.
We found a vendor for latex-free mylar balloons and he recommended using wine spouts to connect the balloon to the bottles as he had fielded this question before.
2nd Grade – Structure and Properties of Matter
PS1.B: Chemical Reactions
Heating or cooling a substance may cause changes that can be observed. Sometimes these changes are
reversible, and sometimes they are not. (2-PS1-4)
5th Grade – Structure and Properties of Matter
Structure and Properties of Matter
PS1.B: Chemical Reactions
When two or more different substances are mixed, a new substance with different properties may be formed. (5-PS1-4)
No matter what reaction or change in properties occurs, the total weight of the substances does not change. (Boundary: Mass and weight are not distinguished at this grade level.) (5-PS1-2)
By Laura Hospitál
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