NAME: _______________________________ PERIOD: ______ Chemical Reactions Part 2 Packet - Regular
Components → 8.6.3 - 8.6.6
Agenda ● Conservation of Matter Notes → 1
0 Minutes → Page 2 ● Conservation of Matter Lab → 20 Minutes → Pages 3 ­ 4 ● Counting Atoms Notes → 10 Minutes → Page 5 ● Counting Atoms Worksheet → 10 Minutes → Page 6 ● Conservation / Counting Atoms Quiz → 10 Minutes ● Take the Conservation / Counting Atoms Quiz TOMORROW ● If you score less than a 70% ▪ Re­watch the notes video, study, retake the quiz TOMORROW ● Balancing Equations Notes → 20 Minutes → Pages 7­8 ● Balancing Equations Interactive → 20 Minutes → Page 9 ● Balancing Equations Worksheet → 20 Minutes → Pages 10­11 ● Balancing Equations Quiz → 10 Minutes ● Take the Balancing Equations Quiz TOMORROW ● If you score less than a 70% ▪ Re­watch the notes video, study, retake the quiz TOMORROW ●
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Endothermic / Exothermic Notes → 10 Minutes → Page 12 Endothermic / Exothermic Worksheet → 1
0 Minutes → Page 13 Endothermic / Exothermic Lab Part 1 → 20 Minutes → Pages 14 Endothermic / Exothermic Lab Part 2 → 30 Minutes → Pages 15­16 Endothermic / Exothermic Quiz → 10 Minutes ● Take the Endothermic / Exothermic Quiz TOMORROW ● If you score less than a 70% ▪ Re­watch the notes video, study, retake the quiz TOMORROW ● Endothermic / Exothermic Device Lab → 8
0 Minutes → Pages 17­19 ● Chemistry Part 2 Study Guide → 2
0 Minutes ● Pick up the study guide from the front of the room ● Complete the study guide by the date written on the board 1 NAME: _______________________________ PERIOD: ______ Conservation of Matter Notes •
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Chemical Reac樀猄ons – Happen all of the 樀猄me – Happen naturally or can be man made – Can be physical or chemical Law of Conserva樀猄on of Ma䐀猄er • Ma䐀猄er cannot be ___________ o
r ___________ ! • The total amount of ma䐀猄er remains ___________ • Even though the ma䐀猄er may change from one form to another, the same number of atoms exists before and a縂ꬅer the change takes place! • The mass of the ___________ m
ust equal the mass of the ___________ . • Evidence • The elements on the reactant side = the elements on the products • The # of each element on the reactant side = the # of each element on the product side • The mass of the reactants = the mass of the products Example: Tin Fluoride – Tin + hydrogen fluoride → tin fluoride + hydrogen •
What’s the total mass of the reactants? •
So what should the mass of the products be? 2 NAME: _______________________________ PERIOD: ______ Conservation Lab “You can’t get something from nothing” Background: • The conservation of mass tells us that you cannot destroy or create matter. In this lab I want you to prove it! Materials: • 1 zip lock bag • 2 small plastic cups • acetic acid • sodium bicarbonate • beakers • balance Data: Change in mass (g) Initial Mass (g) Final Mass (g) (Final mass – Initial mass) Plastic Bag Beaker Plastic Bag Procedure: 1. Place 2 g of sodium bicarbonate into a small plastic cup. 2. Place 10 mL of acetic acid into a small plastic cup. 3. Put both cups in the plastic bag. Take care NOT to spill the contents of either cup. 4. Seal the plastic bag. 5. Determine the mass of the cups and their contents, and the plastic bag. Write the values in your data table. 6. Without opening the bag, pour the vinegar into the cup of baking soda. 7. Observe 8. Without opening the bag, record the mass of the contents of the plastic bag. Take care not to break the seal of the plastic bag. Beaker Procedure: 1. Place 2 beakers on the balance 2. Press zero 3. Measure 2 g of sodium bicarbonate in the smaller beaker (50 mL) 4. Pour 20 mL of acetic acid into the larger beaker (100 mL) 5. Write your mass in your data table. 6. Without spilling, pour the baking soda into the vinegar ● DO NOT DO THIS ON THE BALANCE 7. Observe 8. Record the mass of the contents of the beakers. (Both beakers should be on the balance) 3 NAME: _______________________________ PERIOD: ______ Analysis Questions: 1. Describe what happens when the acetic acid was poured into the cup of sodium bicarbonate 2. Is this a chemical reaction? What evidence do you have to support your answer? 3. How does the change of mass from the plastic bag relate to the change of mass from the beaker? 4. Why do you think the changes in mass are different? 5. What is the conservation of mass? 6. Which set up (plastic bag or beaker) demonstrates the conservation of mass more accurately? Plastic Bag
Beaker 7. Why? 8. How does the chemical equation support the conservation of matter? 4 NAME: _______________________________ PERIOD: ______ Counting Atoms Notes Wri樀猄ng Compounds • Coefficient – Number ___________ t he element/compound – Tells you how many of the ___________ / _ __________ there are – Applies to everything a縂ꬅer the coefficient up un樀猄l the + or → • Example: 2H 2 O = The 2 coefficient is distributed to the H 2 and the O • Total = 4 Hydrogen (2 x 2 = 4) and 2 Oxygen (2 x 1 = 2) • Subscript – Number ___________ the element ‐ lower right side – Tells you how many ___________ o
f that element there are – Example: H 2 O → The 2 subscript only applies to the Hydrogen and not the Oxygen. – Subscripts and parenthesis • If a subscript is a縂ꬅer a parenthesis “( )” then it applies to everything inside of it • Example: (H 2 O) 2 = The 2 subscript applies to the H 2 O • Total = 4 Hydrogen (2 x 2 = 4) and 2 Oxygen (2 x 1 = 2) • Coun樀猄ng Atoms in a Compound Prac樀猄ce – CaCO3 • Ca = • C = • O = – C9H8O4 • C = • H = • O = – Mg(OH)2 • Mg = • O = • H = – 2FeS2 • Fe = • S = – H2O + O2 • H = • O = – 2C7H5(NO2)3 • C = • H = • N = • O = 5 NAME: _______________________________ PERIOD: ______ Counting Atoms Worksheet List the number of atoms of each element within the compound below. C = 2 O = 4
Compound NaCl BaCl2 LiBr FeS2 BaSO4 CaSO4 3CaCO2 C6H4Cl2 C2H4O2 Mg(OH)2 2HBr 3H20 2C202 C7H5(NO2)3 2 Ca(H2PO4)2 Atoms in Compound Na = Cl = Ba = Cl = Li = Br = Fe = S = Ba = O = S = Ca = O = S = Ca = O = C = C = Cl = H = C = O = H = Mg = H = O = H = Br = H = O = C = O = C = N = H = O = Ca = P = H = O = 6 NAME: _______________________________ PERIOD: ______ STOP! TAKE THE CONSERVATION /
COUNTING ATOMS QUIZ
Balancing Equation Notes
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Why do we need to be balanced? – All atoms that are on the ______________________ are also on the ______________________ • Remember the Conserva樀猄on of Mass Law Steps to balancing Equa樀猄ons 1. Count the # of atoms on each side 2. Add Coefficients where necessary ● NEVER CHANGE OR ADD SUBSCRIPTS! 3. Recount the # of atoms on each side 4. Con樀猄nue adding coefficients un樀猄l the number of atoms on each side are equal. 5. Reduce the coefficient to the lowest terms (Hint: Start with 2 and see where it gets you!) Hints to Remember – Order for Balancing • ___________ → ___________ • Metals • Ions • Non‐Metals • Oxygen • Hydrogen • Balance Oxygen and Hydrogen LAST! Step 1: Count the # of atoms of each side •
Step 2: Add Coefficients where necessary •
Step 3: Recount the # of atoms on each side •
Step 4: Con樀猄nue adding coefficients un樀猄l the number of atoms on each side are equal. •
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Prac樀猄ce Balancing Equa樀猄ons ___ Na + ___ Cl 2 →___ NaCl •
Addi樀猄onal Prac樀猄ce • ___ CH 4 + ___ O 2 → ___ CO 2 + ___ H 2 O • ___ Li + ___ HNO 3 → ___ LiNO 3 + ___ H 2 •
___ AgNO 3 + ___ Cu → ___ Cu(NO 3 ) 2 + ___ Ag • ___ Al + ___ O 2 → ___ Al 2 O 3 8 NAME: _______________________________ PERIOD: ______ Balancing Equations Interactive Part 1: Counting Atoms ● For each chemical formula in the table, list each element that is in the compound. Write both the element symbol and the number of each element present. Name and Use Formula Atoms in Formula Silicon Dioxide (Sand) SiO 2 Butane (Lighter Fluid) C 4 H 10 Iron (III) Oxide (Rust) Fe 2 O 3 Sulfuric Acid (Car Ba䐀猄eries) H 2 SO 4 Magnesium hydroxide (Milk of magnesia) Mg(OH) 2 Sucrose (Sugar) C 12 H 22 O 11 Trinitrotuluene (TNT ‐ Explosives) C 7 H 5 (NO 2 ) 3 Calcium dihydrogen phosphate (Fer樀猄lizer) Ca(H 2 PO 4 ) 2 Part 2: Balancing Equations 1. If the instruc樀猄ons below are confusing, watch the 2 minute instruc樀猄on video on the science website. 2. For each reac樀猄on listed, follow steps 3‐9 below 3. Select a different colored chip to represent each different atom (ex. Red for oxygen atoms, blue for hydrogen atoms) 4. Build one molecule of each reactant on the le縂ꬅ side of your table 5. Build one molecule of each product on the right side of your table 6. Place the notecard arrow in between the reactants and products 7. Count all of the atoms of each element on the reactants and products side 8. If the number of each atom is equal, the equa樀猄on is balanced. If the number is not equal, add addi樀猄onal molecules to the appropriate side(s) un樀猄l the total number of elements on both sides are equal 9. Count the total number of each molecule (NOT ATOM) that you have constructed in the equa樀猄on. Place coefficients in front of the appropriate molecule in the correct equa樀猄on below. ____ H 2 + _____ O 2 → __ __ H 2 O _____ Si + _____ Cl 2 → _____ SiCl 4 _____ Al + _____ O 2 → _____Al 2 O 3 _____ N 2 + _____H 2 → _____ NH 3 _____ K + _____ H 2 O → _____ KOH + _____ H 2 _____ Na + _____ Cl 2 → _____ NaCl _____ CH 4 + _____ O 2 → _____ CO 2 + _____ H 2 O _____ HgO → _____ Hg + _____O 2 9 NAME: _______________________________ PERIOD: ______ Balancing Equations Worksheet Balance the following below: 1. _____Na + _____ MgF 2 → ______ NaF + ______ Mg 2. _____Mg + _____ HCl → ______ MgCl 2 + ______ H 2 3. _____Cl 2 + _____ KI → _____ KCl + _____ I 2 4. _____ HNO 3 + _____ Mg(OH) 2 → _____ H 2 O + _____ Mg(NO 3 ) 2 5. _____ H 3 PO 4 + _____ NaBr → _____ HBr + _____ Na 3 PO 4 6. _____ Na + _____ O 2 → _____ Na 2 O 10 NAME: _______________________________ PERIOD: ______ 7. _____ C + _____ H 2 → _____ C 3 H 8 8. _____ Fe 2 O 3 + _____ H 2 O → _____ Fe(OH) 3 9. _____ C 2 H 2 + _____ H 2 → _____ C 2 H 6 10. _____ CuSO 4 + _____ NaOH → _____ Cu(OH) 2 + _____ Na 2 SO 4 11. _____ CF 4 + _____ Br 2 → _____ CBr 4 + _____ F 2 12. _____ Hg 2 I 2 + _____ O 2 → _____ Hg 2 O + _____ I 2 13. _____ C 7 H 16 +_____ O 2 → _____ CO 2 + _____ H 2 O 11 NAME: _______________________________ PERIOD: ______ STOP! TAKE THE BALANCING QUIZ
Endothermic and Exothermic Reaction Notes •
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Chemical Reac樀猄ons • Indicators of Chemical Reac樀猄ons • ______________________ • Odor Change • Gas produced → New substance not just boiling • Bubbles produced → Must be a new gas and not just boiling • Gives off a precipitate • Temperature Change • ______________________ / ______________________ Temperature Changes • 2 Different Types • Endothermic • Endo = ___________ • Therm = Temp • Heat taken In; Reac樀猄on becomes warmer but surrounding temperature drops • Exothermic • Exo = ___________ / ___________ • Therm = Temp • Heat released; Reac樀猄on loses heat but surrounding temperature rises Endothermic Exothermic •
A reac樀猄on that ___________ / __________ in heat •
A reac樀猄on that ___________ h
eat •
More energy is supplied than released •
More energy is released than supplied •
Temperature ___________ •
Temperature ___________ •
Occurs when the bonds between atoms break (energy is absorbed) •
Occurs when atoms bond together (energy is released) •
Examples: • Photosynthesis • Mel樀猄ng Ice Cubes • Evapora樀猄on of water • Baking Bread • Cooking an Egg •
Example: • Burning fossil fuels • A candle flame • Iron Rus樀猄ng • Camp Fire • Volcanic Erup樀猄ons 12 NAME: _______________________________ PERIOD: ______ Exothermic and Endothermic Reaction Worksheet All chemical reac樀猄ons involve energy. Exothermic reac樀猄ons are chemical reac樀猄ons in which energy is released. Endothermic reac樀猄ons are chemical reac樀猄ons in which energy is absorbed. 1. A chemical reac樀猄on in which energy is absorbed is called a. Endothermic reac樀猄on. b. Oxida樀猄on reac樀猄on. c. Ac樀猄va樀猄on reac樀猄on. d. Exothermic reac樀猄on. 2. A chemical reac樀猄on in which energy is released is called an a. Endothermic reac樀猄on. b. Oxida樀猄on reac樀猄on. c. Ac樀猄va樀猄on reac樀猄on. d. Exothermic reac樀猄on. Write EX if the reaction is exothermic. Write EN if the reaction is endothermic. 3. __________ A cake bakes 4. __________ Oil is burned 5. __________ Fireworks explode 6. __________ When two chemicals mix their temperature rises 7. __________ A solid burns brightly and releases heat, light and sound 8. __________ When two chemicals are mixed their temperature drops 9. __________ Two chemicals will only react if you heat them con樀猄nually 10. __________ Plants take in light energy for photosynthesis 11. __________ Clay turns into brick when it is heated in a kiln at high temperatures 12. __________ Dead plant material decays, producing warm compost 13. __________ Logs burning in a fireplace 14. _________ Electricity being used to change water into hydrogen and oxygen gas 15. _________ Gasoline burning in an automobile engine 16. _________ Plants using sunlight, carbon dioxide, and water to make sugar and oxygen 17. _________ The explosion of dynamite 13 NAME: _______________________________ PERIOD: ______ Endothermic / Exothermic Lab - Part 1 Hypothesis: ●
If I combine baking soda and vinegar then the temperature of the vinegar will _____________. Materials ­ Part 1 ­ Endothermic ●
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Plastic Bag Graduated Cylinder Thermometer Baking soda Plastic Cup Vinegar Procedure ­ Part 1 ­ Endothermic 1.
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Pour 20 mL of vinegar into an empty plastic bag. Feel the bag. Observe and record how the temperature feels in the data table below. Place the thermometer in the bag. Make sure the bulb of the thermometer is in the solution. Record the temperature of the vinegar below. Leave the thermometer in the bag. Measure 5 g of baking soda using the scale Carefully pour the baking soda into the bag and gently mix. (Be careful—the chemical reaction will cause foam to fill the bag.) 7. Wait 30 seconds and record the temperature again. 8. Remove the thermometer from the bag and carefully zip the bag. 9. Feel the bag again and note how the temperature change feels. Record your observations below Data ­ Part 1: Endothermic Vinegar Vinegar + Baking Soda General Observations Exact Temperature Part 1 ­ Analysis Questions: 1. How do you know a reaction occurred? 2. How did the temperature of the vinegar change when combined with baking soda? 3. Why do you think this happened? 14 NAME: _______________________________ PERIOD: ______ Endothermic / Exothermic Lab - Part 2 Hypothesis : ●
If I combine water and calcium chloride then the temperature of the water will _____________. Materials ­ Part 2 ­ Exothermic ●
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Plastic Bag Graduated Cylinder Measuring Spoons Thermometer Water Calcium chloride Procedure ­ Part 2 ­ Exothermic: 1. Pour 20 mL of water into an empty plastic bag. Feel the bag. Observe and record how the temperature feels in the data table below. 2. Place the thermometer in the bag. Make sure the bulb of the thermometer is in the water. 3. Record the temperature below. Leave the thermometer in the bag. 4. Carefully pour 5 g of calcium chloride into the water and gently mix. 5. Wait 30 seconds and record the temperature again. 6. Remove the thermometer from the bag and carefully zip the bag. 7. Feel the bag again and note how the temperature change feels in the data table below. Data ­ Part 2: Exothermic Water Water + Calcium Chloride General Observations Exact Temperature Part 2 Analysis Questions: 1. How do you know a reaction occurred? 2. How did the temperature of the water change when combined with calcium chloride? 3. Why do you think this happened? 15 NAME: _______________________________ PERIOD: ______ Part 1 and 2 Analysis Questions: Read the “What Was Happening” article and answer the following questions. 1. What does endothermic mean? 2. What does exothermic mean? 3. Complete the table below for Part 1 of the lab. Reactants General Name Baking Soda + Vinegar Products _____________ + _____________ + _____________ Compounds NaHCO 3 + CH 3 COOH _____________ + _____________ + _____________ 4. Complete the table below for Part 2 of the lab. Reactants General Name Compounds Products ____________________ + _________________ Calcium Oxide + Hydrochloric Acid CaCl2 + H2O CaO + 2HCl 5. What is a common use for calcium chloride? 6. Explain why calcium chloride would be helpful in the winter. Make sure you mention temperature changes and how this might help. 16 NAME: _______________________________ PERIOD: ______ STOP! TAKE THE ENDO/ EXO QUIZ
Endothermic and Exothermic Device Lab Instructions Challenge: ● You must design a self­cooling device or object. You can design any type of device, but your design must use the chemicals to cool it in a safe way. Your device can be for any situation where it might be useful: everyday use, military, skiing, hiking, fishing, boating, etc. Materials: ● Plastic Bag / Beaker ● Graduated Cylinder ● Measuring Spoons ● Thermometer ● Water ● Acetic Acid ● Sodium Bicarbonate ● Calcium chloride Procedure: 1. Brainstorm an idea for a device you think should be created. Write that device and its description below. Feel free to draw pictures! 2. Why would your device be useful / necessary? 3. Which combination of solids and liquids would be most useful in your device? Sodium Bicarbonate and Acetic Acid
Calcium chloride and Water 17 NAME: _______________________________ PERIOD: ______ 4. Your next step is to decide how much of each solid and liquid you would need to use in your device. To help you, complete the steps below. 5. Determine which 4 ratios you plan to use for your test. You can choose from the ones below or create your own ● Maximum amount of samples combined: ● 20 g solid or 20 mL liquid ● Examples: 2 g solid to 2 mL liquid (1:1) 4 g solid to 2 mL liquid (2:1) 6 g solid to 2 mL liquid (3:1) 8 g solid to 2 mL liquid (4:1) 10 g solid to 2 mL liquid (5:1) 2 g solid to 4 mL liquid (1:2) 2 g solid to 6 mL liquid (1:3) 2 g solid to 8 mL liquid (1:4) 2 g solid to 10 mL liquid (1:5) 6. Write the ratios you plan to use in the data table below 7. Confirm your ratios with your teacher ● YOU MUST CONFIRM YOUR RATIOS BEFORE YOU START TESTING 8. Test the ratios on your data table and record your results ● Make sure you take careful measurements 9. Clean up your lab station 10. Answer the analysis questions Data Table: Solid Amount Liquid Amount Ratio Temperature Before Temperature After Change in Temperature Reflection: 1. Which ratio would be the best for your device? 2. Why is this ratio the best? 3. Are there any other ratios you would like to test? If so, why? 18 NAME: _______________________________ PERIOD: ______ 4. How did the thermal energy change as you mixed the solid and the liquid together? Thermal energy was released
Thermal energy was absorbed 5. What type of reaction occurred? Endothermic
Exothermic 6. If you had to actually design your device, what areas might be an issue / what problems would still need to be worked out before your device could be sold? ● ● ● ● ● ● ● ● ● ● 19 NAME: _______________________________ PERIOD: ______ STOP! Complete the following steps
1. Go page by page and make sure every
question is answered
2. Make sure you check in your packet so
you can get points
3. Make sure you have taken EVERY quiz
● Conservation / Counting Atoms
● Balancing Equations
● Endo / Exo
4. Complete the study guide at the front
of the room
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