Hemet High  Chemistry Name:Pd:

Chapter 8 Homework Packet

Date
Assigned / Date
Due / Assignment / Stamp
All Notes Completed and Attached / ____/10 pts
Ch 8.1 pg 274 #1-3
and pg 290 #1-2, 13
Ch 8.2 pg 284 #1-2 and pg 291 #27 (write formulas, balance, & classify)
Balancing Worksheet #1 and #2
Balancing & Classifying Worksheet #3
Ch 8.2 and 8.3 pg 284 #4
and pg 287 #2-3
Types of Reactions Worksheet #1
Types of Reactions Worksheet #2
Ch 8 Review Worksheet
Due end of Class on Tuesday!
Final Packet / ___/90

Test is

Hemet High • Chemistry

8 ● Chemical Equations and Reactions

NOTES

Section 1: Balancing Equations

Indications of a Chemical Reaction

Evolution of energy as ______and ______.

Production of a ______

Formation of a ______

______Change

Characteristics of Chemical Equations

  • The equation must represent known ______.
  • The equation must contain the correct ______for the reactants and products.
  • The law of conservation of ______must be satisfied.

Chemical Reactions

Chemical equations give information in two major areas:

1. ______and ______of the reaction.

2. ______of a balanced chemical equation tell us the ______of the substances involved.

Example of a Balanced Chemical Equation: 2H2 (g) + O2 (g) 2H2O (g)

Review: Reactants are on the ______side of the arrow, and the products are on the ______side. The arrow means “______” or “to produce”.

Common Symbols used in Chemical Equations:See table 2 on page 266

Balancing Chemical Equations

Why do you have to balance a chemical equation?

Law of Conservation of Matter (Mass): Matter is neither created nor destroyed in chemical reactions.

During a chemical reaction, atoms are either ______, separated, or rearranged. The ______and type of each atom stays the same.

How do you balance a chemical equation?

Coefficients are placed in ______of the substances involved in the chemical reaction to get the same ______of atoms of each element on both sides of the equation.

Rules for Balancing Chemical Equations

(1) Coefficients can only be placed in ______of a chemical formula.

Practice Problems: How many atoms of each type are indicated in the following compounds?

(a) 2 (NH4)3PO4N= H= P= O=

(b) 4 KC2H3O2 K= C= H= O=

(c) 3 Ca(NO3)2 Ca= N= O=

(2) You cannot change a ______!!

Example : H2 + O2  H2O

To balance oxygen, you cannot change water’s formula to______!!

(3) You cannot place the coefficient in the ______of a formula!!

Example : Al + N2  AlN

To balance nitrogen, you cannot put a 2 in the middle to make ______!

(4) Reduce the coefficients to the simplest ______ratio.

Example: H2 + O2  H2O can be reduced to… H2 + O2  H2O

(5) Get rid of any ______! Coefficients must be ______numbers! You can’t have a ______of a molecule or atom!

Example: 1H2 + ½O2  1H2O changes to… H2 + O2  H2O

Balancing Equations: “Helpful Hints”

a) Balance elements that appear in more than one compound ______

(NH4)2CO3  NH3 + CO2 + H2O

b) Balance ______as though theyareone item as long as the ion stays together as a group on each side of the arrow.

Al + CuSO4  Al2(SO4)3 + Cu

c) If you can’t seem to get it balanced, ______and begin with a different element the next time, or put a “ _____” somewhere and then try again.

Li + H2O  LiOH + H2

•This is what I’ll constantly be telling you to do if you are stuck and you need my help... “Pick an element to balance. How many are on the left side? How many are on the right side? ______!!!

Fe(OH)3  Fe2O3 + H2O

Example

•Aluminum is a good choice for outdoor furniture because it reacts with oxygen in the air to form a thin protective coat of aluminum oxide. Write word, formula, and chemical equations for this reaction.

Word:

Formula:

Chemical Equation:

Section 2: Five Types of Reactions

General Types of Reactions

1) ______:A reaction that breaks apart ______into simpler substances, (usually two elements or an element and a smaller compound.)

General Form:AX  A + X

Examples:

Remember that “H2,N2,O2,F2,Cl2,Br2, and I2” elements are diatomic when alone!!

•Remember to balance the equation after you write the products.

2) ______(sometimes called Combination): A reaction of ______, typically a metal and a nonmetal to form ______. It is the opposite of decomposition.

General Form: A + X  AX

Examples:

3) ______: Reacts with oxygen gas!!! A reaction between a Carbon/Hydrogen with ______always produces the same… CO2 + H2O

This reaction is too easy!! Don’t miss it!

General Form: CxHy + O2CO2 + H2O

Examples:

4) ______Displacement:A reaction between ______and ______that produces a different ______and ______.

General Forms: AX + Y  AY + X or AX + B  BX + A

Examples:

5) ______Displacement:A reaction between ______that are dissolved in water that produces ______, one of which is ______.

Water or a gas may be one of the two compounds being produced.

General Form: AX(aq) + BY(aq)  AY(aq) + BX(s)

A solid produced during a chemical reaction is called a ______.

Examples:

Sections 2 and 3: Types of Reactions and Activity Series

Making Synthesis Reactions

•Metals with nonmetals ______compoundsMg + O2  MgO

•Nonmetals with nonmetals ______compoundsC + O2 CO2

•Metal Oxides react with water to form ______. CaO + H2O  Ca(OH)2

•Nonmetal Oxides react with water to form ______.SO2 + H2O  H2SO3

Decomposition

•Decomposition of Binary CompoundsHgO  Hg + O2

•Decomposition of Metal CarbonatesCaCO3 CaO + CO2

•Decomposition of Metal HydroxidesCa(OH)2 CaO + H2O

•Decomposition of Metal ChloratesKClO3 KCl + O2

•Decomposition of AcidsH2CO3 CO2 + H2O

Combustion

•Remember, these ______produce CO2 and H2O.

Single Displacement

The element that is trying to replace the other must be more reactive than the one it is replacing.

You must use the ______to see if the reaction will happen.

The Higher up it is = the more reactive it is

Elements from Li to Na can displace hydrogen in water to form a metallic hydroxide and H2 gas.

Single Replacement Reactions

NaCl + F2  _____ + _____ Remember the

FeCl2+ K  _____ + _____ Activity Series!

HCl + Zn  _____ + _____ Table 3 on page 286

HCl + Au  _____ + _____

H2O + Na  _____ + _____

H2O + Fe  _____ + _____

AgNO3+ Cu  _____ + _____

Metals Replace MetalsAl + Pb(NO3)2 Pb + Al(NO3)3

•Metals Replace Hydrogen in WaterNa + H2O  NaOH + H2

•Metals Replace Hydrogen in AcidMg + HCl  H2 + MgCl2

•Halogens replace halogens below them

Double Displacement

•Switch the compounds and make sure the new compounds are ______.

•They will ______react and switch, no activity series needed.

KI + Pb(NO3)2 PbI2 + KNO3

Once you have solved for the products of the reaction, you must then balance the reaction!