Gas Production Lab

We have already seen a few of the signs or evidence of a chemical change. The MOM lab showed us permanent color change and the precipitate lab showed us two liquids can form a solid.

Remember the signs of gas production?

•Bubbling•Foaming•Fizzing•Or sometimes a smell is produced.

Safety First

You will need to wear your goggles and tie back your hair. Remove your ID’s or swing them around to the back so they are out of the way.

Journaling

Title: Gas productionGuiding Question: What evidence do you see to support a chemical change?Chart:

I notice…. I wonder….

Step 1

Examine your supplies and write a description of each in the I notice column.•Yeast •Hydrogen Peroxide (H2O2)•Wooden Splint

The Wooden Splint

The wooden splint will be used during the lab in a special way, so there are some instructions you need for it’s use. You will light it and let it burn for a few seconds, then blow it out, so you have an ember, what you have on the end of a punk. It needs to be glowing. DO NOT LIGHT IT YET! You will use it to test the gas produced.

Step 2

•Make a before drawing of the materials.•Pour the hydrogen peroxide into the yeast.•Observe and record what happens. Feel the bottom of the cup!•Make an after drawing of the materials.

Ok, now light the splint!

•Touch the ember to one of the bubbles.•Record your observations in your I notice column.•Draw a before and after picture of the splint.• If you have an ember still let one of your lab partners touch a bubble and see what happens. If you don’t have an ember relight the splint and then let your lab partners touch a bubble.

Clean Up

•Run water over the splint.•All materials can be thrown away.

What happened?

•The yeast acts a catalyst and causes the hydrogen peroxide (H2O2) to turn into water (H2O).

Conclusion

•Write a sentence describing the evidence you saw that proves what occurred was a chemical change.

Something to think about.

Earlier this year we exploded a hydrogen balloon. We were able to do this because hydrogen is flammable.The gas we created today did not explode. It helped the splint to burn, because wood is flammable.

What was that gas?

• Look back at the elements in the materials you used for this lab.

• Write a sentence to explain what you think the gas was.