Naomi KassKati Maggio

Nolan Dunnigan

Chemical Equations and

Reactions

Definitions

• Precipitate- a solid that is produced as a result of a chemical reaction in solution and that seperates from the solution

• Coefficient- a small whole number that appears in front of a formula in a chemical equation

How to Write a Chemical Equation

Step 1: Find out whether the equation is an ionic or covalent equation-Ionic: use pink sheet (snap it together method, or criss- cross method based off of charges)-Covalent: use the prefixes in the names of the elements in order to find out what the subscripts are

Step 1: This equation is ionic, meaning USE PINK SHEET

Step 2: Find all of the element symbols with their charges. hydrogen= H+1; OH-

1. So.. our first part of the equation would be H+OH.

Step 3 : To find the reactions we can "snap these two together because they have the same charges. We will get H2O

Step 4: Put it all together: H+OH H2O

Hydrogen plus Hydroxide yields Water

Naming Covalent Equations: Rules: 1.Never start with the prefix 'mono"2.Writed the prefix before element/ion

name3.you may need more than one prefix in a

chemical name4. if you add a prefix and have "ao" or

"oo," remove the first vowels Ex: monooxide monoxide

Prefixes

# of Atoms Prefix

1 mono

2 di

3 tri

4 tetra

5 pentra

6 hexa

7 hepta

8 octa

Example: P2O5

The "P" has a subscript of 2 and is the first element in this compound; so it would be diphosphorus.

The "O" in this equation has a subscript of five, so add add the correct prefix and use your pink sheet to find the ending. You will get pentoxide. Put it all together:

Diphosphorus pentoxide.

Just use this process for each of the compounds in your equation!

1. C+O2. P+ H3

3.N2 + O3

Find and Name the Products of each reaction

1. C+O CO- carbon monoxide2. P+ H3 PH3- phosphorus

trihydride3.N2 + O3 N2O3- dinitrogen trioxide

Answers

When balancing equations, you want the same number of atoms of each element on either side of the equation.

Balancing Equations

HI H2 + I2

These 2's act as the subscripts in the chemical equation. The subscripts allow you to figure out how many atoms of each element are present in the equation. In this example there are 2 atoms of Hydrogen as well as 2 atoms of Iodine.In order to balance this equation, you need to make the other side of the reaction equal. To do so, you'll have to put a 2 in front of HI.

Balanced equation: 2HI H2 + I2

Balance these equations: 1.) Fe+ Cl2 FeCl3 2.) Zn+HCl ZnCl2+H2

3.) H2+O2 H2O 4.) Cu+AgNO3 Cu(NO3)2+Ag

Practice Problems

This law states that mass is neither created nor destroyed during ordinary chemical reactions or physical changes.

Law of Conservation of Mass

This law helped scientist to come to the conclusion that regardless of where or how a pure chemical compound is prepared, it is composed of a fixed property of elements.

Use of this law...

There are five different types of chemical reactions:

1.)Synthesis Reaction 2.)Decomposition Reactions3.)Single Displacement Reactions4.)Double Displacement Reactions5.)Combustion Reactions

Chemical reactions

In a synthesis reaction two or more substances combine to form a new compound.

Synthesis equation: A + B AB

In this equation A and B can be elements or compounds, while the product AB is a compound.

Synthesis Reaction

In a decomposition reaction, a single compound undergoes a reaction that produces two or more simpler substances.

(Hint: Remember decomposition and synthesis have opposite reactions)

Decomposition Equation:AB A + B

A and B can be elements or compounds, while the product AB is a compound.

Decomposition Reactions

In single displacement reactions, one element replaces a similar element in a compound.

Single Displacement Equation:A + BC AC + B OrD + BC BD + C

A,B,C, and D are elements, while AC, BC, and BD are compounds

Single Displacement Reactions

In Double displacement reactions, the ions of two compounds exchange places in an aqueous solution to form two new compounds.

Double displacement equation: AB + CD AD + BC

A,B,C, and D in the reactants represent ions. AD and BC represent ionic or molecular compounds

Double Displacement Reactions

In a combustion reaction, a substance combines with oxygen, releasing a large amount of energy in the form of light and heat.

Combustion Reactions

1. PbCl2 + AgNO3 P(NO3)2 + AgCl =_________

2. NH3 + HCl NH4Cl = _____________

3.C12H22O11 + O2 CO2 + H2O = __________

4. H2SO4 + Fe H2 + FeSO4 = ___________

5.Al2S3 Al + S = _________

Lets play what's the reaction?

1.) Double Displacement

2.) Synthesis

3.) Combustion

4.) Single Displacement

5.) Decomposition

The Reaction was....

An activity series is a list of elements organized according to the ease with which the elements undergo certain chemical reactions.

With the use of the activity series, you have the ability to predict if the reaction occurs.

Activity Series

Goodnight.....