Pop Rocks and Mountain Dew – Is it CC or PC? Adapted from http://science.howstuffworks.com/innovation/science-questions/question114.htm What are Pop Rocks made of? Hard candy (like a lollypop or a Jolly Rancher) is made from sugar, corn syrup, water and flavoring. You heat the ingredients together and boil the mixture to evaporate the water. You are left with a pure sugar syrup. Why do Pop Rocks Pop? Part 1 The gas inside pop rocks is Carbon Dioxide (CO2). Carbon dioxide gas is pumped into hot sugar syrup at about 600 pounds per square inch (psi). The CO2 gas forms a froth mixture with the syrup. When it cools this leaves tiny, tiny bubbles inside the candy. Why do Pop Rocks Pop? Part 2 Once the syrup cools, it hardens and is shattered into pieces. Some CO2 gas is released in this process, but individual pop rock pieces still contain many tiny bubbles of CO2 under lots and lots of pressure. When you put the candy in your mouth, it melts (just like hard candy) and releases the bubbles with a POP! What you are hearing and feeling is the 600-psi carbon dioxide gas being released from each bubble. Do you need a liquid to pop a pop rock? Do you? If you take the end of a spoon and press the pop rock, what happens? The pop rock explodes because you cracked the candy shell and the CO2 which was pressure from the inside escaped. What about the soda? When soda is made, the manufacturers force carbon dioxide into the liquid at high pressure up to 1,2000 pounds per square inch. The “fsst” you hear when you open a can of soda is millions of CO2 molecules escape out of the opening. What about the color change? Pop Rocks are colored because of a dye called artificial color (Red #40 or some other color dye). When a dye like food coloring is added water, it is only a physical change. The color of the water did change, but the original water molecules stayed the same. There are no new molecules made. The food coloring dye moves into the space occupied between the water molecules. The more food coloring you add the darker the liquid looks. Did the molecules change? Chemistry is about studying the properties (measurements) and the changes of matter. When looking at the changes of matter, it’s important to think about the molecules before the change and the molecules after the change. A physical change is a change where the molecules in the matter change size, shape or state but they do not become new molecules. A chemical change is a change where the molecules in the matter break their bonds and make new bonds to make new molecules. The evidence is seen as a change of color, light, temperature or gas (usually bubbles or a smell) Pop Rocks and Mountain Dew Background Info. Adapted from http://science.howstuffworks.com/innovation/science-questions/question114.htm What are Pop Rocks made of? Hard candy (like a lollypop or a Jolly Rancher) is made from sugar, corn syrup, water and flavoring. You heat the ingredients together and 1._____ the mixture to 2._____________the water. What is left is a sugary 3. ______. Why do Pop Rocks Pop? Part 1 The gas inside pop rocks is 4._______________. 5._______________ is pumped into hot sugar syrup at about 6._____ pounds per square inch (psi). The 7._____ forms a froth mixture with the syrup. When it cools this leaves tiny, tiny 8.___________ inside the syrup. Why do Pop Rocks Pop? Part 2 Once the syrup cools, it hardens and is shattered into pieces. Some 9. ______ is released in this process, but individual pop rock pieces still contain many tiny bubbles of 10._____ under lots and lots of pressure. When you put the candy in your mouth, it 11.________ (just like hard candy) and releases the bubbles with a POP! What you are hearing and feeling is the 600-psi of 12._____________ being released from each bubble. Do you need a liquid to pop a pop rock? If you take the end of a spoon and press the pop rock, what happens? The pop rock 13. _____________ because you cracked the candy shell and the 14.__________ which was under 15.____________ from the inside escaped. What about the soda? When soda is made, the manufacturers force 16.__________ into the liquid at high 17.___________ up to 1,2000 pounds per square inch. The “fsst” you hear when you open a can of soda is millions of 18._______ molecules escape out of the opening. What about the color change? Pop Rocks are colored because of a chemical 19._____ When a 20._____ like food coloring is added water, it is only a 21.__________ change. The color of the water did change, but the original water 22.____________ stayed the same. There are no new 23.__________ made. The food coloring 24._____ moves into the space occupied between the water 25.____________. It is possible to use filters to remove the dye, and get clean, clear water. Did the molecules change? Chemistry is about studying the properties (measurements) and the changes of matter. When looking at the changes of matter, it’s important to think about the 26.__________ before and after the change. A physical change is a change where the 27.__________ in the matter change size, shape or state but they do not become new 28.__________. A chemical change is a change where the 29.__________in the matter break their bonds and make new bonds to make new 30.__________. The evidence of a chemical change is seen as a change of color, light, temperature or gas (usually bubbles or a smell). Pop Rocks and Mountain Dew – Is it CC or PC? Name:_______________________ Before it explodes… Draw the pop rock candy in the soda. Include CO2 molecules in your drawing Date: __________ After it explodes… Draw the pop rock candy in the soda. Include CO2 molecules in your drawing. Based on the background information from the front… Is this a physical change or a chemical change? Claim: It is my opinion that this reaction is a _________________________ change. *** Claims are statements that you believe to be true and that answer a scientific question. *** Evidence is a factual information. It can be observations or data from experiments that support the claim. My evidence is ________________________________________________________ _____________________________________________________________________ ***Reasoning is explaining how the claim and the evidence fit together. Elaborate! Show what you know!!! My reasoning is ________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ Claim: It is my opinion that this reaction is not a _______________________ change. *** Claims are statements that you believe to be true and that answer a scientific question. *** Evidence is a factual information. It can be observations or data from experiments that support the claim. My evidence is ________________________________________________________ _____________________________________________________________________ ***Reasoning is explaining how the claim and the evidence fit together. Elaborate! Show what you know!!! My reasoning is ________________________________________________________ _____________________________________________________________________ _____________________________________________________________________ 1. Boil 2. Evaporate 3. Syrup 4. Carbon Dioxide 5. Carbon Dioxide 6. 600 7. Gas 8. Bubbles 9. Carbon Dioxide 10. CO2 11. Melts 12. Carbon Dioxide 13. Explodes 14. Carbon Dioxide 15. Pressure 16. Carbon Dioxide 17. Pressure 18. CO2 19. Dye 20. dye 21. physical 22. molecules 23. molecules 24. dye 25. molecules 26. molecules 27. molecules 28. molecules 29. molecules 30. molecules Extra Credit Use the information in the article to help you draw the following. Pop Rock Before Exploding. Label CO2 Pop Rock After Exploding. Label CO2 Is the popping of a pop rock PC or CC? Why? What is your evidence? ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ Extra Credit Use the information in the article to help you draw the following. Pop Rock Before Exploding. Label CO2 Pop Rock After Exploding. Label CO2 Is the popping of a pop rock PC or CC? Why? Explain the evidence. ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ ________________________________________________________________ Then you let the temperature rise. at about 300º F (150º degrees C). Once it cools, you release the pressure and the candy shatters, but the pieces still contain the high-pressure bubbles (use magnifying glass to see the bubbles). For comparison, a typical car tire holds 32 pounds per square inch (psi) of air pressure. 600 pounds psi is a lot of pressure! Dissolving Pop Rocks When a solid dissolve in a liquid this doesn’t mean that the solid becomes invisible. Dissolving means that the bonds holding solid molecules together have broken apart, and the remaining individual atoms are too small to see. The candy shell of pop rocks dissolves in any liquid, and when it does the CO2 gas is released. What about the CO2 Sensor Data? When we did our original mountain Dew and Pop Rocks experiments, we used CO2 sensors to measure the increase of CO2 as the candy dissolved and the gas was released. CO2 was the gas that was released from inside the soda bubbles that floated from the liquid out of the cup and into the air. CO2 was the gas that was released as the pop rocks dissolved. Why does soda “fizz”? The fizz that bubbles up when you crack open a can of soda is carbon dioxide gas (CO2). Soft drink manufacturers add this tingling froth by forcing carbon dioxide and water into your soda at high pressures—up to 1,200 pounds per square inch. The "fssst" you hear is millions of carbon dioxide molecules bursting out of their sweet, watery prisons, where they have been held against their will. When you crack open the can, you release the pressure and allow the gas bubbles to wiggle free from the liquid and rise to the surface. This requires energy because in order for the gas to break free from the liquid it has to overcome the force holding the liquid together. One way to input energy is to shake the beverage. This adds the energy needed to unleash more tiny bubbles and add real splash to a celebration. http://www.livescience.com/32492-why-does-soda-fizz.html Why does soda “fizz”? The fizz that bubbles up when you crack open a can of soda is carbon dioxide gas (CO2). Soft drink manufacturers add this tingling froth by forcing carbon dioxide and water into your soda at high pressures—up to 1,200 pounds per square inch. The "fssst" you hear is millions of carbon dioxide molecules bursting out of their sweet, watery prisons, where they have been held against their will. When you crack open the can, you release the pressure and allow the gas bubbles to wiggle free from the liquid and rise to the surface. This requires energy because in order for the gas to break free from the liquid it has to overcome the force holding the liquid together. One way to input energy is to shake the beverage. This adds the energy needed to unleash more tiny bubbles and add real splash to a celebration. http://www.livescience.com/32492-why-does-soda-fizz.html
