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Chemical Changes October 7, 2012
Ms. SmithMrs. Malone
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.
1. Pick up a new gold Do Now sheet2. Put your CB on your desk3. Copy down this week’s TEKS4. Tape new blue vocabulary onto Pg. 38 and title “Week 7 Vocabulary
– Chemical Changes”5. Read the Do Now “Reading Science!: Formation of a New
Substance”6. Q?: Why do scientists call firefly light “cold light?”
Chemical Changes October 7, 2012
Ms. SmithMrs. Malone
:
Chemical changes occur 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
Group Member Roles October 7, 2011
Ms. SmithMrs. Malone
:
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
Powder Particulars Lab October 7, 2012
Ms. SmithMrs. Malone
:
• Title: Pg. 39 “Powder Particulars”• Hypothesis: I predict…• Materials: dropper bottle of vinegar, dropper bottle of water, micro
chem plate1 ml scoops of baking soda and baking powder • Procedures:
1. How are these powders similar and different?2. Add three drops of water into the baking soda. Add three drops of water in to
the baking powder. Record your observations3. Add three drops of vinegar into the baking soda. Add three drops of vinegar
into the baking powder. Record your observations.
• Observations:
Baking Soda Baking Powder
Powder Particulars Lab October 7, 2012
Ms. SmithMrs. Malone
:
Analysis Questions:
1. What does the baking soda do when vinegar is added?2. What does the baking powder do when vinegar is added?3. How were the reactions alike?4. How were the reactions different?
Conclusion:
In paragraph form complete a lab conclusion. Use page 4 in your CB to complete this assignment.
Powder Particulars Lab October 7, 2012
Ms. SmithMrs. Malone
:
• 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?
Chemical Changes October 8, 2012
Ms. SmithMrs. Malone
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.
1. Put your CB on your desk2. Read the Do Now “Reading Science!:
Formation of a New Substance”6. Q?: What is the main idea of paragraph 2?
Chemical Changes October 8, 2012
Ms. SmithMrs. Malone
:
Chemical changes is when matter has changed into a new substance through a chemical reaction.
color change formation of a gas light production smoke presence of heat
1. 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?
Evidence of a chemical change.
2. Color 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?
Chemical Change
3. 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?
Chemical Change
4. 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?
Chemical Change
A forest fire destroys acres of land. There is a lot of smoke, and the trees turn to charcoal.
ANSWER: YESEVIDENCE: - Smoke, - color change,
- temperature change
Is it a chemical change?
When making hot cocoa, clear water turns brown when you mix the cocoa in.
ANSWER: No(the water is turning brown because the cocoa is brown)
Is it a chemical change?
An old wheelbarrow is left out in the rain and rusts.
ANSWER: YesEVIDENCE: Color change, precipitate forming (rust)
Is it a chemical change?
On a hot day, water forms on the outside of a cold glass of water.
ANSWER: No(No new substance is forming)
Is it a chemical change?
Ice cream melts after it falls on the ground.
ANSWER: No(No new substance is forming)
Is it a chemical change?
A raw egg gets cooked.
ANSWER: YesEVIDENCE: Color change
Is it a chemical change?
When Alka Seltzer is dropped into water it fizzes.
ANSWER: YesEVIDENCE: gas formation
Is it a chemical change?
Crayons change white paper to red.
ANSWER: No(The paper is turning red because the crayon is red.)
Is it a chemical change?
Soda fizzes, and bubbles rise as you pour it in a glass.
ANSWER: No(The bubbles were already there, just under pressure in the bottle.)
Is it a chemical change?
When you crack a glow stick, hydrogen peroxide mix with other chemicals, causing it to glow and warm up.
ANSWER: YesEVIDENCE: - color change
- temperature change
Is it a chemical change?
Chemical Changes October 9-10, 2012
Ms. SmithMrs. Malone
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.
1. Put your CB on your desk2. Tape the Cornell Notes onto Pg. ___ and title
“Chemical Changes Notes”3. 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?
Group Member Roles Block Day Ms. SmithMrs. Malone
:
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
• 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.
Chemical Change
Chemical Changes October 11, 2012
Ms. SmithMrs. Malone
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.
1. Put your CB on your desk2. Tape the Cornell Notes onto Pg. ___ and title
“Chemical Changes Notes”3. Read the Do Now “Reading Science!:
Formation of a New Substance”6. Q?: What are some uses of the chemicals found in fireflies?
