Physical and Chemical Change (Balloon Test:Baking Soda and Vinegar)

1. Focus Question: How can you create a chemical change?

2. Predictions:

1) If we combine vinegar and baking soda, then _________. Turn and talk to your partner to create another prediction about what will happen to our balloon when we combine vinegar and baking soda. 2) If we put together vinegar and baking soda, then our balloon will______.

III. Planning (optional):

            Materials: baking soda, vinegar, water bottles, balloons

            Launch:

            Remember last week we talked about physical change and we put that term on our word wall. Last week we talked a little about physical reactions. How can I physically change this piece of paper? What can I do to this piece of paper to change what it looks like? Students might say: crumple it, fold it, rip it, poke a hole in it, draw on it, etc. No matter what I do to this paper what is staying the same? What do you notice is staying the same? Am I changing this paper into something new? Even though the paper looks different physically it is still paper.

            Let’s talk about something else. How many of you have ever been to a bonfire or have you seen wood burning in a fireplace? What happens to the wood as the fire has been burning for awhile? What did you notice was happening to the wood? Could you take the ashes and put it back together to make wood? How is this different from what we did with the paper? This is a chemical change because the ashes could not turn back into firewood. Let’s add chemical change to our word wall. There are many ways that a chemical change occurs. Our FOCUStoday is “How can you create a chemical change?”                  Going into Investigation:

             Each of you are going to be given a balloon and bottle. In your bottle there will be vinegar and the balloon has baking soda in it. What are some predictions that we can make with the materials we have here? 1) If we combine vinegar and baking soda, then _________. Turn and talk to your partner to create another prediction about what will happen to our balloon when we combine vinegar and baking soda. 2) If we put together vinegar and baking soda, then our balloon will______. Possible predictions: If we combine vinegar and baking soda, then the two will turn into a solid. If we combine vinegar and baking soda, then the two will begin fizzing. If we combine vinegar and baking soda, then the two will create a gas. If we put together vinegar and baking soda, then our balloon will pop. If we put together vinegar and baking soda, then the balloon will fill up with gas. 

            Be careful not to spill the baking soda into the vinegar until you are ready to investigate. Remember as scientists to use your senses to observe as a chemical reaction is occurring. When you get your materials place your balloon opening over your water bottle opening. Carefully pick up your balloon and let the baking soda fall into the bottle. Use your senses observe what is happening inside your water bottle and your balloon?

            Questions for groups: What are you noticing? What happened to the vinegar? What happened to the baking soda? Why did your balloon blow up?

            Come back together: We have already filled out the “What we tried” section on our data chart because we all started off in the same way. Can your groups share with us what happened in your investigation?

IV. Data/Diagram/ Graphs:

               What we tried:                                            What happened:

Balloon filled with baking soda (1 tbsp) Balloon on bottle Vinegar (1/4 cup) in the bottom of bottle

                 

Claims/Evidence: We claim that when you combine a solid and a liquid a chemical reaction can occur. This was evident when we added vinegar to the baking soda and a gas was formed. 

Conclusion: Why did the balloon inflate? We combined our baking soda (solid) and vinegar (liquid) and that made a gas. The gas inflated the balloon. Going back to the paper we talked about earlier, no matter what we did to the paper it was still paper. In this investigation could we take this gas and break it apart to make vinegar and baking soda again? 

Possible Questions: Let’s come up with more questions together that we may have from completing our investigation: Do you think the amount of vinegar and baking soda had to do with the balloon filling up with gas? What other substances can you put together to make a gas?