Chapter 5 Notes

1
Chapter 5 Notes

• Chemical Reactions

2
Chapter 5.1 notes

• Reactants- is a substance(s) that undergoes a
  chemical change.
• Yields- is the arrow in the reaction
• Products- is a substance(s) that is the result of
  a chemical reaction
• Reactants Products

3

• Chemical reaction- produces new substance(s)
• Signs of chemical reaction
• Production of a gas
• Change in color
• Production of heat or light

4

• Chemical energy- the energy stored within the
  atoms and molecules that can be released when a
  substance reacts
• Energy is equal on both sides of the
  reactionenergy can NOT be created or destroyed
  only changed from form to form.
• Chemical energy can be changed to
• Heat, Electrical, Mechanical, Light

5

• Exothermic reaction- a reaction that transfers
  energy from the reactants to the surroundings as
  heat
• Exergonic are exothermic reactions
• Endothermic reaction- a reaction in which energy
  is transferred to the reactants as heat from the
  surroundings
• Endogonic are endothermic reactions.

6
Chapter 5.2 Notes

• Synthesis reaction- a reaction of at least two
  substances that form a new more complex compound.
  
• AB C
• Plus signs only on the left
• Decomposition reaction- a reaction in which one
  compound breaks into at least two products.
• C AB
• Plus signs only on the right

7

• Single replacement reaction- a reaction in which
  atoms of one element take the place of atoms of
  another element in a compound.
• ABX?BAX
• Double replacement reaction- a reaction in which
  a gas, a solid precipitate, or a molecular
  compound is formed from the apparent exchange of
  ions between two compounds.
• AXBY?AYBX

8
Chapter 5.3 Notes

• Chemical Equation- an equation that uses chemical
  formulas and symbols to show the reactants and
  products in a chemical reaction.
• Mole ratios- the smallest relative number of
  moles of the substances involved in a reaction

9
Balancing Equations

• Make a T-chart
• Put the number of each element on the t-chart
• If the of atoms are not the same you need to
  balance. You can only add COEFFICIENTS (Big )
• 4. Check work! Count all s of each element.

H2 O2 H2O
Right
Left
H 2
2
O 2
1
10
Chapter 5.4 Notes

• Factors affecting reaction rates
• High temperature
• More Surface area
• Higher concentration
• Higher pressure
• Agitation (stirring, Mixing)

11

• Catalysts- speed up chemical reactions. Shown in
  chemical reactions above the yields
• Enzymes are proteins that are catalyst in living
  things.
• Inhibitors- slow down chemical reactions

Heat
12

• Equilibrium systems- is a balanced state. The
  number of molecules leaving is to the number of
  molecules entering.

13

• Reversible reactions have double arrows.
• Le Chateliers Principle states if a change is
  made to a system, the equilibrium shirts to
  oppose the change until a new equilibrium is
  reached.

Products
Reactants
14
Work Cited

• Cartoon. Feb 8, 2008. http//www.beaconhurst.sti
  rling.sch.uk/departments/science/chem7.jpg
• Test tube. Feb 8, 2008. http//www.chemistryteac
  her.net/lessons/img/chemreactions2_clip_image002_0
  001.jpg
• Bubbles. Feb. 8 , 2008. http//www1.istockphoto.
  com/file_thumbview_approve/628957/2/istockphoto_62
  8957_co2_bubbles_in_water.jpg
• Fire. Feb. 8, 2008. http//www.destination360.co
  m/north-america/us/nevada/burning-man.php
• Hot Cocoa. Feb. 13, 2008. http//www.companyscom
  ing.com/images/freestuff/recipes/Caramel20Hot20C
  hocolate.jpg
• Equilibrium. Feb 13, 2008. http//www.chem4kids.
  com/files/art/reaction_equilib1_240.jpg
• reversible reactions. Feb. 13, 2008.
  http//dbhs.wvusd.k12.ca.us/webdocs/Equilibrium/eq
  uib-for-rev-reaction.GIF