chapter 5 chemical reactions
Download
Skip this Video
Download Presentation
Chapter 5 Chemical Reactions

Loading in 2 Seconds...

play fullscreen
1 / 14

Chapter 5 Chemical Reactions - PowerPoint PPT Presentation


  • 149 Views
  • Uploaded on

Chapter 5 Chemical Reactions. I. 5.1 Nature of Chemical Reactions II. 5.2 Reaction Types III. 5.3 Balancing Chemical Equations. I. 5.1 Nature of Chemical Reactions. A. Signs of a chemical reaction 1. bubbles are given off 2. changes in color 3. precipitates are formed

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Chapter 5 Chemical Reactions' - cissy


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
chapter 5 chemical reactions
Chapter 5 Chemical Reactions
  • I. 5.1 Nature of Chemical Reactions
  • II. 5.2 Reaction Types
  • III. 5.3 Balancing Chemical Equations
i 5 1 nature of chemical reactions
I. 5.1 Nature of Chemical Reactions
  • A. Signs of a chemical reaction
    • 1. bubbles are given off
    • 2. changes in color
    • 3. precipitates are formed
    • 4. energy is released or absorbed
  • B. Chemical reactions rearrange atoms
slide3
1. Reactants - a substance that undergoes a chemical change

a. bonds are broken

b. energy is added in the form of

(1) heat

(2) electricity

(3) sound

(4) light

slide4
2. Products - a substance that is the result of a chemical reaction

a. bonds are formed

b. energy is released in the form of

(1) heat

(2) light

(3) sound

slide5
3. Reactions can be referred to as

a. Exothermic - a reaction that transfers energy from the reactants to the surroundings usually as heat

b. Endothermic - a reaction in which energy is transferred to the reactants usually as heat from the surroundings

ii 5 2 reaction types
II. 5.2 Reaction Types
  • A. Classifying Reactions
    • 1. We use patterns to identify the general types of chemical reactions
slide7
a. Synthesis reactions

(1) a reaction of at least two substances that form a new, more complex compound

(2) general form

(a) A + B g AB

(b) 2 Na + Cl2g 2 Na Cl

i) subscript indicates the number of atoms per molecule

ii) coefficients indicates the number of molecules

iii) g is read as yields

slide8
b. Decomposition Reactions

(1) a reaction in which one compound breaks into at least two products

(2) general form

(a) AB g A + B

(b) 2 H2O g 2 H2 + O2

(3) electrolysis is the decomposition of a compound by an electric current

slide9
c. Single Replacement (displacement) Reactions

(1) a reaction in which atoms of one element take the place of atoms of another element in a compound

(2) general form

(a) XA + B g BA + X

(b) 3 CuCl2 + 2 Al g 2 AlCl3 + 3 Cu

(3) combustion a reaction in which a compound and oxygen burn

(a) 2 CH4 + 4 O2g 2 CO2 + 4 H2O

slide10
d. Double Replacement (displacement) Reactions

(1) a reaction in which a gas, a solid precipitate, or a molecular compound is formed from the apparent exchange of ions between two compounds

(2) general form

(a) AX + BY g AY + BX

(b) Pb(NO3)2 + K2CrO4g PbCrO4 + 2 KNO3

slide11
e. Reduction/Oxidation (redox) reaction is a reaction that occurs when electrons are transferred from one reactant to another.

(1) reduced - substance that accept electrons

(2) oxidized - substance that gives up electrons

iii 5 3 balancing chemical equations
III. 5.3 Balancing Chemical Equations
  • A. Four Steps for Balancing Chemical Equations
    • 1. Determine the type of reaction.
      • a. D - Decomposition
      • b. S - Synthesis
      • c. SR - Single Replacement
      • d. DR - Double Replacement
slide13
2. Recombine ions/atoms on the product side.

a. different free elements and different compounds

3. Balance compounds on the product side

a. using subscripts

b. check for diatomic elements

(1) only for Decomposition and Single Replacement reactions

slide14
4. Balance equation by placing coefficients in front of each compound or free element where necessary

a. Conservation of matter

b. must have the same number of atoms for each element on both sides of the equation

5. Examples

a. Mg + O2g

S

2 Mg + O2g 2 MgO

b. Pb(NO3)2 + KI g

DR

Pb(NO3)2 + 2 KI g PbI2 + 2 KNO3

c. N2 + H2g

d. NaCl g

ad