Summary

In this lab, students will make a lemon fizzy drink. Students will discuss what happens when things are mixed together. This is a fundamental question that young students often wonder. Mixing things together, or chemistry, is a common occurrence in everyday life. Introducing chemistry vocabulary better prepares students for understanding what is happening in the world around them.

Grade Level

Elementary school

Objectives

By the end of this lesson, students should be able to

• understand what a chemical reaction is.
• use appropriate “science” vocabulary to discuss their observations.
• make real world connections to the science experiment.

Chemistry Topics

• Reactions
• Chemical Change
• Physical Change
• Physical Properties

Time

Teacher Preparation: 45 minutes

Lesson: 1 hour

Materials

• lemons (one half per student )
• disposable drinking cups (one per student)
• chilled drinkable water
• measuring half teaspoons (1 per group)
• baking soda (enough for every student to have one half teaspoon)
• packets of sugar (enough for every student to have two)
• stirring sticks (one per student)
• paper towels
• goggles for every student
• know/want to learn/learned (KWL) chart

Safety

• Know of any allergies students may have prior to the experiment.
• Food should never be consumed in a lab setting. This experiment should not take place in a lab or in an area close to chemicals.
• Always wear safety goggles when handling chemicals in the lab.
• Students should wash their hands thoroughly before leaving the lab.
• When students complete the lab, instruct them how to clean up their materials and dispose of any chemicals.

Teacher Notes

• Parent support for this activity is recommended, as it requires close supervision (1:6).
• Mixed ability grouping would be very beneficial to differentiate instruction for all students.
• As an extension for older students, teachers could discuss states of matter around this lesson-students work with all three states in this lesson.
• The drink may not taste yummy, so encourage just a small taste.
• Vocabulary:
  
  • Chemist- Chemists study various chemical elements and compounds, their properties and how they work together in our bodies and the world around us.
  • Chemical reaction- A chemical reaction is a process where a set of substances undergo a chemical change to form a different substance.
  • Physical Change- A physical change involves a change in a physical property. Some examples of physical properties include melting, vaporization, strength, durability, texture, shape, size, color, volume and density.
  • Mixture- mixtures are absolutely everywhere you look. Most things in nature are mixtures. Look at rocks, the ocean, or even the atmosphere. They are all mixtures, and mixtures are about physical properties. That statement means the individual molecules are near each other, but their fundamental chemical structure does not change while they are part of the mixture. If the chemical structure changed when mixed, it would be called a chemical reaction.
• To start the lab, I suggest you play the song “It’s Called Chemistry” by Kim Mitzo Thompson. Then tell students that they are going to be chemists today and learn about chemical reactions. Ask the students (pre-lab) what they know about chemical reactions. Have students record their ideas on sticky notes and place them on the “Know” column of the class KWL chart. The class will participate in a short discussion of their ideas.
• During the experiment this is what is happening:
  • The students create a mixture with the lemon juice, water, and sugar, but by adding the baking soda, it reacts with the acid in the lemon juice to produce CO₂, which is a chemical change. The mixture should be bubbly once the baking soda substance is added to the lemon juice substance. After the sugar is added it will taste a little like a fizzy lemonade soda pop. The bubbles that form when you add the baking soda to the lemon mixture are carbon dioxide (CO₂), these are the same bubbles you find in pop. Of course, the pop companies add other flavored sweeteners and a lot more sugar. The carbon dioxide bubbles formed because we created a chemical reaction when we added the lemon (acid) to the baking soda (a base).

Cross-Disciplinary Extensions

Connect to Math

Students will take a survey of which classmates liked the lemon fizzy drink and who did not. Next, students will make a tally chart of their data. Then, students will make a picture graph (with single-unit scale) to represent the data set. Finally, students will solve simple put-together, take-apart, and compare problems using information presented in the bar graph.

Connect to Reading

To introduce the concept of physical and chemical changes, share the story Thunder Cake by Patricia Polacco. Work as a whole group to retell the story. Talk about how all the different ingredients get mixed together and how they change. Discuss physical changes using the idea of mixing flour and sugar together–they stay the same despite being mixed. Talk about chemical changes with baking the cake as an example. To help solidify the concepts of physical and chemical changes, use BrainPop Jr and show the video on chemical and physical changes.

Connect to Writing

Have students summarize the experiment, explain what a chemical reaction is, and how knowing about chemical reactions can help them better understand the world around them.

Connect to Social Studies

Invite a local chemist into the classroom and explain his/her job. The chemist should explain how his/her job changes history and helps our community, how his/her job has changed the local community over time, and be able to describe how his/her job has helped identify a problem in our community’s past and described how it was resolved.