Chemical Reactions Chapter 7.1. Objectives Recognize some signs that a chemical reaction is taking...
-
Upload
elisabeth-walsh -
Category
Documents
-
view
218 -
download
0
Transcript of Chemical Reactions Chapter 7.1. Objectives Recognize some signs that a chemical reaction is taking...
![Page 1: Chemical Reactions Chapter 7.1. Objectives Recognize some signs that a chemical reaction is taking place. Explain chemical changes in terms of the.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649f125503460f94c251c6/html5/thumbnails/1.jpg)
Chemical Reactions
Chapter 7.1
![Page 2: Chemical Reactions Chapter 7.1. Objectives Recognize some signs that a chemical reaction is taking place. Explain chemical changes in terms of the.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649f125503460f94c251c6/html5/thumbnails/2.jpg)
Objectives
Recognize some signs that a chemical reaction is taking place.
Explain chemical changes in terms of the structure and motions of atoms and molecules.
Describe the differences between endothermic and exothermic reactions.
Identify situations involving chemical energy.
![Page 3: Chemical Reactions Chapter 7.1. Objectives Recognize some signs that a chemical reaction is taking place. Explain chemical changes in terms of the.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649f125503460f94c251c6/html5/thumbnails/3.jpg)
Signs of a Chemical Reaction
Release of gas
Change in color
Change in odor
Release of energy
![Page 4: Chemical Reactions Chapter 7.1. Objectives Recognize some signs that a chemical reaction is taking place. Explain chemical changes in terms of the.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649f125503460f94c251c6/html5/thumbnails/4.jpg)
Release of Gas
http://webpub.allegheny.edu/employee/a/asheffie/images/AEScannon.JPG
![Page 5: Chemical Reactions Chapter 7.1. Objectives Recognize some signs that a chemical reaction is taking place. Explain chemical changes in terms of the.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649f125503460f94c251c6/html5/thumbnails/5.jpg)
Change in Color http://genchem.chem.wisc.edu/demonstrations/Images/15precip/pbi.jpg
![Page 6: Chemical Reactions Chapter 7.1. Objectives Recognize some signs that a chemical reaction is taking place. Explain chemical changes in terms of the.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649f125503460f94c251c6/html5/thumbnails/6.jpg)
Change in Odor http://www.julieleung.com/archives/cheesewhey.jpg
![Page 7: Chemical Reactions Chapter 7.1. Objectives Recognize some signs that a chemical reaction is taking place. Explain chemical changes in terms of the.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649f125503460f94c251c6/html5/thumbnails/7.jpg)
Release of Energy http://upload.wikimedia.org/wikipedia/commons/thumb/3/36/
Large_bonfire.jpg/250px-Large_bonfire.jpg
![Page 8: Chemical Reactions Chapter 7.1. Objectives Recognize some signs that a chemical reaction is taking place. Explain chemical changes in terms of the.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649f125503460f94c251c6/html5/thumbnails/8.jpg)
Explain why the following are examples of a chemical reaction.
Lighting a match Mixing vinegar and baking soda Grilling a burger Food rotting
![Page 9: Chemical Reactions Chapter 7.1. Objectives Recognize some signs that a chemical reaction is taking place. Explain chemical changes in terms of the.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649f125503460f94c251c6/html5/thumbnails/9.jpg)
Chemical Reactions
Involves rearrangement of atoms. The number and types of atoms are conserved.
Chemical Change Example: In a car or boat engine,
isooctane (C8H18) and oxygen (O2) react to form water (H2O) and carbon dioxide (CO2).
![Page 10: Chemical Reactions Chapter 7.1. Objectives Recognize some signs that a chemical reaction is taking place. Explain chemical changes in terms of the.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649f125503460f94c251c6/html5/thumbnails/10.jpg)
Chemical Reactions
Reactant – a substance that undergoes a chemical change.
Product – a substance that is the result of a chemical change.
![Page 11: Chemical Reactions Chapter 7.1. Objectives Recognize some signs that a chemical reaction is taking place. Explain chemical changes in terms of the.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649f125503460f94c251c6/html5/thumbnails/11.jpg)
Predict which atoms will be found in the products of the following reactions. Mercury (II) oxide, HgO, is heated and
decomposes Hg and O
Limestone, CaCO3, reacts with hydrochloric acid, HCl Ca, C, O, H, and Cl
Table sugar, C12H22O11, burns in air to form caramel C, H, and O
![Page 12: Chemical Reactions Chapter 7.1. Objectives Recognize some signs that a chemical reaction is taking place. Explain chemical changes in terms of the.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649f125503460f94c251c6/html5/thumbnails/12.jpg)
Energy and Reactions
Energy must be added to break bonds. You need a spark to react gasoline and
oxygen so that you can break apart the bonds within the gasoline and oxygen.
Energy is released when forming bonds. After you have broken the bonds between
the gasoline and oxygen, they will form new bonds to create carbon dioxide and water and energy will be released.
![Page 13: Chemical Reactions Chapter 7.1. Objectives Recognize some signs that a chemical reaction is taking place. Explain chemical changes in terms of the.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649f125503460f94c251c6/html5/thumbnails/13.jpg)
Energy and Reactions
The chemical energy of reactants is equal to the chemical energy of the products.
Chemical energy – the energy stored within atoms and molecules that can be released when a substance reacts
![Page 14: Chemical Reactions Chapter 7.1. Objectives Recognize some signs that a chemical reaction is taking place. Explain chemical changes in terms of the.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649f125503460f94c251c6/html5/thumbnails/14.jpg)
Energy and Reactions
Exothermic reaction – a reaction that transfers energy from the reactants to the surroundings usually as heat. Energy is released.
Taken from http://jchemed.chem.wisc.edu/jcesoft/cca/cca3/STILLS/GLYCER/GLYCER/64JPG48/7.JPG
![Page 15: Chemical Reactions Chapter 7.1. Objectives Recognize some signs that a chemical reaction is taking place. Explain chemical changes in terms of the.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649f125503460f94c251c6/html5/thumbnails/15.jpg)
Energy and Reactions
Endothermic reaction – a reaction in which energy is transferred to the reactants usually as heat from the surroundings. Energy is absorbed.
Taken from https://secure.edventures.com/oscart/catalog/images/WIZ_1060-06.jpg
![Page 16: Chemical Reactions Chapter 7.1. Objectives Recognize some signs that a chemical reaction is taking place. Explain chemical changes in terms of the.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649f125503460f94c251c6/html5/thumbnails/16.jpg)
Critical Thinking:
Calcium oxide, CaO, is used in cement mixes. When water is added, heat is released as CaO forms calcium hydroxide, Ca(OH)2.
What signs are there that this is a chemical reaction?
Which has more chemical energy, the reactants or products?
Explain your answer.
![Page 17: Chemical Reactions Chapter 7.1. Objectives Recognize some signs that a chemical reaction is taking place. Explain chemical changes in terms of the.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649f125503460f94c251c6/html5/thumbnails/17.jpg)
1. Identify which of the following is a chemical reaction
a. Melting icephysical
b. Burning a candleChemical reaction
c. Rubbing a marker on paperphysical
d. Rusting ironChemical reaction
![Page 18: Chemical Reactions Chapter 7.1. Objectives Recognize some signs that a chemical reaction is taking place. Explain chemical changes in terms of the.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649f125503460f94c251c6/html5/thumbnails/18.jpg)
2. List four forms of energy that might be absorbed or released during a chemical reaction.
Heat, electricity, light, sound2. List three signs that could make you
think a chemical reaction might be taking place.
Change in color, release of gas, release of energy, change in odor
![Page 19: Chemical Reactions Chapter 7.1. Objectives Recognize some signs that a chemical reaction is taking place. Explain chemical changes in terms of the.](https://reader036.fdocuments.us/reader036/viewer/2022062314/56649f125503460f94c251c6/html5/thumbnails/19.jpg)
4. Classify the following as exothermic or endothermic.
a. Paper burning with a bright flame* exothermic
b. Plastics becoming brittle after being left in the sun* endothermic
c. A firecracker exploding
* exothermic