Chemical Changes

1. Ms. Smith Mrs. Malone Chemical Changes October 7, 2012 • DO NOW: • Date: October 7, 2012 • 6.5 D identify the formation of a new substance by using the evidence of a possible chemical change such as production of a gas, change in temperature, production of a precipitate, or color change. • Pick up a new gold Do Now sheet • Put your CB on your desk • Copy down this week’s TEKS • Tape new blue vocabulary onto Pg. 38 and title “Week 7 Vocabulary – Chemical Changes” • Read the Do Now “Reading Science!: Formation of a New Substance” • 6. Q?: Why do scientists call firefly light “cold light?”

2. Ms. Smith Mrs. Malone Chemical Changes October 7, 2012 • Chemical changesoccur when matter has changed into a new substance through a chemical reaction. • color change • bubbling and fizzing (gas) • light production • smoke • presence of heat or cold • solid precipitate :

3. Ms. Smith Mrs. Malone Group Member Roles October 7, 2011 • Green - Materials Manager • Only person allowed out of seat during lab • Obtains and returns all lab materials • Blue – Safety/Clean-up Manager • Enforces all safety rules (Goggles!!) • Yellow- Activity Director • • Reads directions to the group • • Keeps group on-task • Red - Data Manager • Records all data • Ensures all group members have lab data :

4. Ms. Smith Mrs. Malone Powder Particulars Lab October 7, 2012 • Title: Pg. 39 “Powder Particulars” • Hypothesis: I predict… • Materials: dropper bottle of vinegar, dropper bottle of water, micro chem plate1 ml scoops of baking sodaand baking powder • Procedures: • How are these powders similar and different? • Add three drops of water into the baking soda. Add three drops of water in to the baking powder. Record your observations • Add three drops of vinegar into the baking soda. Add three drops of vinegar into the baking powder. Record your observations. • Observations: :

5. Ms. Smith Mrs. Malone Powder Particulars Lab October 7, 2012 • Analysis Questions: • What does the baking soda do when vinegar is added? • What does the baking powder do when vinegar is added? • How were the reactions alike? • How were the reactions different? • Conclusion: • In paragraph form complete a lab conclusion. Use page 4 in your CB to complete this assignment. :

6. Ms. Smith Mrs. Malone Powder Particulars Lab October 7, 2012 • Watch this! • You added an acid to your powders to see how their chemical properties could help you tell them apart. • I will add a pH indicator called “Universal Indicator” to two identical looking powders. • Universal Indicator changes color depending on the pH of the substance it touches. • pH tells you how acidic or basic something is. • Do I have two identical powders or two different powders? How can you tell? :

7. Ms. Smith Mrs. Malone Chemical Changes October 8, 2012 • DO NOW: • Date: October 9, 2012 • 6.5 D identify the formation of a new substance by using the evidence of a possible chemical change such as production of a gas, change in temperature, production of a precipitate, or color change. • Put your CB on your desk • Read the Do Now “Reading Science!: Formation of a New Substance” • 6. Q?: What is the main idea of paragraph 2?

8. Ms. Smith Mrs. Malone Chemical Changes October 8, 2012 • Chemical changesis when matter has changed into a new substance through a chemical reaction. • color change • formation of a gas • light production • smoke • presence of heat :

9. Evidence of a chemical change. • Formation of a gas • When you mixed baking soda or baking powder and vinegar, the bubbles you saw were CO2 gas. • Can you think of any examples of bubbling that do not create a new substance?

10. Chemical Change • Color is a property of how the molecule is arranged. If there is a change to the molecule, the color can change. • Color change doesn’t always mean that a chemical change occurred. • Can you think of any examples of a substance changing color that does not create a new substance? 2. Color Change

11. Chemical Change • Temperature Change • The substance can get warmer or cooler, depending on whether the molecules give energy while swapping places (warmer), or need energy to swap (cooler). • Temperature change doesn’t always mean that a chemical change occurred. • Can you think of any examples of a substance getting warmer or colder that do not create a new substance?

12. Chemical Change • Formation of a Precipitate • A precipitate forms when a substance come out of solution, and form a solid. • Formation of a precipitate doesn’t always mean that a chemical change occurred. • Can you think of any examples of solids forming in a liquid that do not create a new substance?

13. Is it a chemical change? ANSWER: YES EVIDENCE: - Smoke, - color change, - temperature change A forest fire destroys acres of land. There is a lot of smoke, and the trees turn to charcoal.

14. Is it a chemical change? ANSWER: No (the water is turning brown because the cocoa is brown) When making hot cocoa, clear water turns brown when you mix the cocoa in.

15. Is it a chemical change? ANSWER: Yes EVIDENCE: Color change, precipitate forming (rust) An old wheelbarrow is left out in the rain and rusts.

16. Is it a chemical change? ANSWER: No (No new substance is forming) On a hot day, water forms on the outside of a cold glass of water.

17. Is it a chemical change? ANSWER: No (No new substance is forming) Ice cream melts after it falls on the ground.

18. Is it a chemical change? ANSWER: Yes EVIDENCE: Color change A raw egg gets cooked.

19. Is it a chemical change? ANSWER: Yes EVIDENCE: gas formation When Alka Seltzer is dropped into water it fizzes.

20. Is it a chemical change? ANSWER: No (The paper is turning red because the crayon is red.) Crayons change white paper to red.

21. Is it a chemical change? ANSWER: No (The bubbles were already there, just under pressure in the bottle.) Soda fizzes, and bubbles rise as you pour it in a glass.

22. Is it a chemical change? ANSWER: Yes EVIDENCE: - color change - temperature change When you crack a glow stick, hydrogen peroxide mix with other chemicals, causing it to glow and warm up.

23. Ms. Smith Mrs. Malone Chemical Changes October 9-10, 2012 • DO NOW: • Date: October 9-10, 2012 • 6.5 D identify the formation of a new substance by using the evidence of a possible chemical change such as production of a gas, change in temperature, production of a precipitate, or color change. • Put your CB on your desk • Tape the Cornell Notes onto Pg. ___ and title “Chemical Changes Notes” • Read the Do Now “Reading Science!: Formation of a New Substance” • 6. Q?: In paragraph 3 of this passage, what does the word • efficient mean?

24. Ms. Smith Mrs. Malone Group Member Roles Block Day • Blue - Materials Manager • only person allowed out of seat during lab • obtains and returns all lab materials • Green- Safety/Clean-up Manager • enforces all safety rules • Red- Activity Director • • reads directions to the group • • keeps group on-task • Yellow - Data Manager • records all data • ensures all group has lab data :

25. Chemical Change • A chemical change occurred when universal indicator was added to cream of tartar and laundry detergent. • Universal indicator is an indicator, because it contains molecules that change color when an acid or base is added to them. • Cream of tartar is an acid, so it gave particles to the indicator, making it turn from purple to red. • Laundry detergent is a base, so it took particles from the indicator, making it turn from red back to purple.

26. Ms. Smith Mrs. Malone Chemical Changes October 11, 2012 • DO NOW: • Date: October 11, 2012 • 6.5 D identify the formation of a new substance by using the evidence of a possible chemical change such as production of a gas, change in temperature, production of a precipitate, or color change. • Put your CB on your desk • Tape the Cornell Notes onto Pg. ___ and title “Chemical Changes Notes” • Read the Do Now “Reading Science!: Formation of a New Substance” • 6. Q?: What are some uses of the chemicals • found in fireflies?