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Dihydrogen Monoxide!!!!!!!!. Why????. Chemistry Joke!. If H 2 0 is water, what is H 2 0 4 ? Drinking, bathing, washing, swimming … All kinds of things!. The name Game. What’s in a name??? How many people can you “bond” with!? You must turn in to me a piece of paper with…
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Dihydrogen Monoxide!!!!!!!! Why????
Chemistry Joke! If H20 is water, what is H204? Drinking, bathing, washing, swimming… All kinds of things!
The name Game What’s in a name??? How many people can you “bond” with!? You must turn in to me a piece of paper with… • Your element and it’s oxidation number • A total of 6 IONIC COMPOUND formulas • AND the name of those compounds
Try these covalent molecules… Carbon monoxide • CO • CO2 • N5H8 • TeBr2 • Si3S7 Carbon dioxide Pentanitrogen octahydride Tellurium dibromide Trisilicon heptasulfide
FLASHBACK 1. How many oxygen atoms are there in bleach, NaClO, AKA sodium hypochlorite? 2. Acetone (CH3COCH3), or nail polish remover, has how many total hydrogen atoms? 3. How do you determine oxidation #’s? 4. What is the oxidation # of Al, O, & Cl ? 5. Write ionic formulas: (find charges 1st then criss-cross!!) Mg + F Be + N 6. Name the following compounds: N5H8 SrCl2
More naming practice • COVALENT: • NO • NO2 • N2O • IONIC: • NaF • ZnCl • CaCl2
Electron diagrams H 1. Electron Dot Diagram: 2. Pictorial Diagrams: Hydrogen: H Oxygen: Water: H2O O H O Covalent bonds! H
Chemical Changes and Chemical Reactions
Physical Changes Occur when the size or shape of the substance is changed Occasionally, the color can change, too Regardless,the original substance(s) do not change Evidences of Physical Changes: - Bending, stretching, heat, and cooling can all cause a physical change ***All phase changes are physical changes
Chemical changes Occurs when there is a change in the arrangement of atoms so that a different substance with different properties is produced Very often, there is some kind of evidence (for example, the formation of a gas)
Evidence of a chemical change • Formation of a gas • Reaction with acids (like this picture of copper reacting with nitric acid) • (Sometimes) a color change can indicate a chemical change. - A good example of this is metal tarnishing Is a neutralization reaction a chemical change?
Bubbles/fizzing/formation of a gas Precipitate formed Energy change Color change Odor… Evidence of chemical REACTIONs
Chemistry Joke! If you're not part of the solution… You're part of the precipitate!
FLASHBACK • 1. What is the main difference between a chemical and physical change? • 2. If a reaction forms a gas, you know it is a ______________ change. • 3. If something changes color, you know it’s a chemical change. True False • 4. Name the four evidences of a chemical rxn. • 5. Explain a situation in which bubbling occurs, but it is NOT a chemical change.
Excuse me… • Coke and other soft drinks are carbonated • Carbonation occurs when carbon dioxide is dissolved in water or solution • This gives the "fizz" to carbonated beverages • Excess gas needs out of the stomach.. So we burp!
Using the materials provided: 1. 2 pieces of Alka-Seltzer 2. 1 film canister 3. Water …you are to build a projectile! Rocket Lab Time!!
Hypothesizing Pick ONE question to answer and generate a hypothesis and WRITE IT DOWN… Use an “If-Then” statement! 1. How does changing the volume of water effect the time/height of rocket “launch”? 2. How does changing the amount of Alka-Seltzer effect the time/height of rocket “launch”?
Lab Report You are to write a brief lab report on your experience… - Skip lines between headings - Full sentences! Alka seltzer Title Hypothesis: (your question) Data: Table? List? Conclusion: tell me what you learned (in paragraph form!) 1. What evidence did you see of a chemical reaction taking place? How does this relate to the lab? 2. Refer back to your hypothesis… was it right or wrong?? Why?? 3. What would have done differently… or how would you make this lab better?
FLASHBACK • EOC WORKBOOK • Pg. 41 (all) • An exothermic reaction __________________ heat. • An endothermic reaction __________________ heat. • ( A + B AB ) is an example of a _____________ reaction
Naming: 2) P2O5 ___________________________ 3) Mg3N ___________________________ 5) SiO2 ____________________________ 6) BaCl2 _______________________________ 8) B2P9 _____________________________________ Formulas: 14) aluminum nitride ____________________ 16) disulfur pentaphosphide ____________________ 17) potassium sulfide __________________________ 18) rubidium iodide ____________________________ 20) hexacarbon dichloride ______________________
Chemical Reactions and Equations: What do they mean? What do they show?
Energy changes in reactions During any chemical reaction, there is an energy change. 1. Exothermic reaction: heat is released during the reaction, gets hot! 2. Endothermic reaction:heat is absorbed during the reaction, gets cold!
The airbag's inflation system reacts sodium azide (NaN3) with potassium nitrate (KNO3) to produce nitrogen gas. Hot blasts of the nitrogen inflate the airbag. Everyday Exothermic and Endothermic Reactions • AIRBAGS! • The airbag's inflation system reacts sodium azide (NaN3) with potassium nitrate (KNO3) to produce nitrogen gas. Hot blasts of the nitrogen inflate the airbag. • Instant Cold Packs • Instant heat packs
Videos • Exothermic vs. Endothermic • Endothermic Reaction
Equation Terms A. Reactants: original substances entering a chemical rxn - what you started with, on the left side B. Products: resulting substances - what you end with, on the right side Reactants Products
Endothermic vs. Exothermic Calcium Chloride vs. Sodium Bicarbonate… who will win the temperature war??? Turn into me:Half sheet of paper
Classifying reactions 1. Synthesis: 2 substances combine to form 1 substance A + B -> AB 2. Decomposition: 1 substance breaks down (decomposes) to 2 substances AB -> A + B (opposite of synthesis) 3. Single Displacement: 1 element replaces another A + BC -> AC + B 4. Double Displacement: positive ion of one compound replaces positive ion of another AB + CD -> AD + CB
Name that equation! Synthesis • 4Al + 3O2 --> 2Al2O3 • Ca(OH)2 --> CaO + H2O • Zn + CuSO4 --> ZnSO4 + Cu • Cl2 + 2KBr --> 2KCl + Br2 • BaCl2 + Na2SO4 --> 2NaCl + BaSO4 • 2H2 + O2 --> 2H2O Decomposition Single Displacement Single Displacement Double Displacement Synthesis
FLASHBACK Label the following equations: (4types) Zn + HCl ZnCl2 + H2 2. Fe + O2 Fe2O3 3. SiO2 + HF SiF4 + H2O 4. FeS + HCl H2S + FeCl2 5. In lab yesterday, what gas produced the signature “popping” sound? Single Displacement Synthesis Double Displacement Double Displacement
Common Gas Lab! CO2 You will be conducting reactions to produce 5 different common gases and observe their chemical and physical properties. A. NaHCO3 + HCl NaCl + H20 + ______ B. Cu + 4HNO3 Cu(NO3)2 + 2H20 + 2 _____ C. NH4Cl + NaOH NaCl + H20 + ______ D. 2H2O2 2H2O + ____ E. Mg + 2HCl MgCl2 + ____ NO2 NH3 O2 H2
FLASHBACK Section Review Pg. 645 #1, 3 EOC REVIEW Pg. 656 #1-5, 11, 15
FLASHBACK EOC WORKBOOK Pg. 43 [all]
Balancing Chemical Equations
Chemical Reactions • Chemical reaction - is the process of changing reactants to products by a chemical change • Chemical reactions are symbolized by • Reactants Products • (s) solid; (l) liquid; (g) gas; (aq) aqueous are the physical states of the reactants and products
Equations show… ___Mg(s) + __ O2(g) __ MgO(s) • The reactants which enter into a reaction. • The products which are formed by the reaction. • The amounts of each substance used and each substance produced. 2 2
Subscripts and coefficients • We use subscripts to balance compounds • CaCl2 • subscripts cannot be changed • We use coefficients to balance equations • 2NaCl+ _ Ca(OH)2 2NaOH +__CaCl2
Balancing equations! • Goal: to get the same number of atoms on both sides of the equation __ Al + __ O2 ___ Al2O3 __ NaCl __ Na + __ Cl2 __ Li + __ H2O __ LiOH + __ H2
What’s the point????? • A balanced chemical equation represents the process of a chemical reaction in which atoms are rearranged but not created or destroyed. • By balancing chemical equations, you show that mass is conserved… Law of Conservation of Mass!
Law of Conservation of Mass Mass is neither created nor destroyed in an ordinary chemical or physical reaction Mass of Reactants = Mass of Products
LAB: Looking at the… Law of Conservation of mass!!!
FLASHBACK Balance the following equations: ___Zn + ___HCl ___ZnCl2 + ___H2 2. ___Fe + ___O2 ___Fe2O3 3. ___SiO2 + ___HF ___SiF4 + ___H2O 4. ___FeS + ___HCl ___H2S + ___FeCl2 5.What is the overall goal of balancing equations?
FLASHBACK 1. __S8 + __O2 __SO2 3. __BeCl2 + __KOH __Be(OH)2 +__KCl 4. __S8 + __ O2 __ SO3 5. __H3PO4 + __Mg(OH)2 __Mg3(PO4)2 + __H2O Balance the following equations: 2. __ HgO __Hg + __ O2
Reaction Rates! Reactions occur when particles of reactants collide with energy
Factors affecting reaction rates • Temperature: higher temperature, reaction rate increases • Particles moving faster, more collision between particles • Concentration: when reactants are more concentrated, rate of reaction increases • More particles mean more collisions
Factors affecting reaction rates 3. Surface Area: more surface area, reaction rate increases 4. Catalyst: presence of catalyst speeds up reaction without being permanently changed [Inhibitor: slows down a reaction] Video!
Thursday 10/22 - Bellringer EOC WORKBOOK Pg. 45 [# 2-6] Pg. 46 [# 1-6]
Salt: Up close and personal Make some observations of salt under a microscope!! • http://www.sciencenetlinks.com/lessons.php?BenchmarkID=4&DocID=173 • http://www.sciencenetlinks.com/lessons.php?BenchmarkID=4&DocID=173 • http://www.mos.org/sln/sem/sem.html