Types of Reactions

Synthesis

• A synthesis reaction is when two or more reactants combine to form a compound.

Formula:  A + B --> C

Examples:

• 1Ca + 1Cl₂ --> 1CaCl₂
• Na + Cl₂ --> 
• 2Na + 1Cl₂ --> 2NaCl
• 1H₂ + 1F₂ -->  2HF
• Al + Cl₂ -->  
• 2Al + 3Cl₂ --> 2AlCl₂
• 6Li + 1N₂ --> 2Li₃N

Decomposition

• A decomposition reaction is when a compound degrades into two or more products.

Formula:  A --> B + C

Examples:

• 2H₂O --> 2H₂ + 1O₂
• KNO₃ -->
• 2KNO₃ --> 2KNO₂ + 1O₂
• NF₃ --> 1N₂ + 3F₂
• MgO -->
• 2MgO --> 2Mg + 1O₂
• 2NaCl --> 2Na + 1Cl₂

Single Replacement

• A single replacement(or displacement) reaction is when one element replaces another element in a compound.

Formula for Metal:  A + BC --> AC + B

Formula for Non-Metal:  A + BC --> BA + C

Examples:

• 6K + 1Al₂O₃ --> 3K₂O + 1Al
• Al + FeCl₂ -->
• 2Al + 3FeCl₂ --> 2AlCl₃ + 3Fe
• 2AgCl + 1Mg --> 2Ag + 1MgCl₂
• Zn + H₂SO₄ -->
• 1Zn + 1H₂SO₄ --> 1ZnSO₄ + 1H₂
• 1Cl₂ + 2KBr --> 2KCl + 1Br₂

Activity Series

• Elements higher on the chart can replace elements below it, but elements lower on the chart cannot replace elements higher on the chart.

For example:

Fe + Al2O3 --> N.R., because iron is lower on the activity series chart than aluminum, it cannot replace it. When this occurs we label it N.R. for no reaction.

Balancing Equations

The number of atoms on the reactant side has to equal to the number of atoms on the product side.

Examples:

• Fe + S --> Fe₂S₃
• 2Fe + 3S --> 1Fe₂S₃
• H₂O -->  H₂ + O₂
• 2H₂O -->  2H₂ + 1O₂
• Al + HCl -->  AlCl₃ + H₂
• 2Al + 6HCl -->  2AlCl₃ + 3H₂
• C₂H₆ + O₂  -->  CO₂   +  H₂O
• 2C₂H₆ + 5O₂  -->  2CO₂   + 6H₂O
• Zn + HCl --> ZnCl₂ + H₂
• 1Zn + 2HCl --> 1ZnCl₂ + 1H₂
• Al + Pb(NO₃)₂ --> Al(NO₃) + Pb
• 2Al + Pb(NO₃)₂ --> 2Al(NO₃) + Pb
• KClO₃ --> KCl + O₂
• 2KClO₃ --> 2KCl + 3O₂
• KOH + H₃PO₄ --> K₃PO₄ + H₂O
• 3KOH + 1H₃PO₄ --> 1K₃PO₄ + 3H₂O
• Al + CuCl₂ --> AlCl₃ + Cu
• 2Al + 3CuCl₂ --> 2AlCl₃ + 3Cu

Translating Word Equations and Naming Compounds

Translating Word Equations

1. First thing is to understand the wording of the word equations.

• The word "and" or "reacts with" means + 
• The phrase "react to," or "produce" means ------>

For example:


Magnesium bromide and chlorine produce magnesium chloride and bromine.


    
    2.  You then look at the Periodic Table for the elements in the equation and criss-cross the numbers in front of the charges on the ions.


MgBr₂  +  Cl₂  ---->   MgCl₂  +  Br₂

Examples:

• Iron and sulfur produces iron(III) sulfide
• Fe + S --> Fe₂S₃
• Water produce hydrogen and oxygen
• H₂O -->  H₂ + O₂
• Potassium and water react to produce potassium hydroxide and hydrogen
• K + H₂O -->  KOH + O₂
• Aluminum and hydrochloric acid produce aluminum chloride and hydrogen
• Al + HCl -->  AlCl₃ + H₂
•  Ethane and oxygen react to produce carbon dioxide and water
• C₂H₆ + O₂  -->  CO₂   +  H₂O

Naming Compounds

• Non-metals end with "ide"

• - ic if the anion name ends in - ate.
• - ous if the anion name ends in - ite.

Acid	Ion	Name
H2SO4	SO4 2-	sulfuric acid (anion, sulfate)
HClO3	ClO3 -	perchlorous acid (anion, perchlorite)

• Roman numerals are needed when naming elements with more than one ion.

Element	Cation	Preferred Name
copper	Cu+	copper (I)
	Cu2+	copper (II)
iron	Fe2+	iron (II)
	Fe3+	iron (III)
lead	Pb2+	lead (II)
	Pb4+	lead (IV)
mercury	Hg22+	mercury (I)
	Hg2+	mercury (II)
tin	Sn2+	tin (II)
	Sn4+	tin (IV)

Roman Numeral Prefixes:

Greek Prefixes	Number
mono-	1
di-	2
tri-	3
tetra-	4
penta-	5
hexa-	6
hepta-	7
octa-	8
nona-	9
deca-	10

Examples:

• Zn + HCl --> ZnCl₂ + H₂
• Zinc + hydrochloric acid --> zinc chloride + hydrogen
• Al + Pb(NO₃)₂ --> Al(NO₃) + Pb
• Aluminum + lead(II) nitrate -->  aluminum nitrate + lead
• KClO₃ --> KCl + O₂
• Potassium chlorate -->  Potassium chloride + oxygen gas
• KOH + H₃PO₄ --> K₃PO₄ + H₂O
• Potassium hydride + phosphoric acid --> potassium phosphate + water
• Al + CuCl₂ --> AlCl₃ + Cu
• Aluminum + copper(II) chloride --> aluminum chloride + copper

Molar Volume of a Gas at STP

Molar Volume:

• The volume occupied by one of a gas is called as molar volume.
• One mole of any gas at STP will have a volume of 22.4 L.
• S.T.P. = Standard Temperature and Pressure
• Standard Temperature = 0^oC or 273 K

Formula:
Molar Volume :  22.4 L of gas / 1 mol of gas  


                                       OR


                       1 mol of gas / 22.4 L of gas

Example:
For the information on Molar Volume, skip to 5:20 of the video:
http://www.youtube.com/watch?v=mwVBg9SMKPg


By: Hikari Hoshika

Diluting Solutions to Prepare Workable Solutions



Moles of solute stays the same,
concentration depend on amount of water



Chemicals are shipped around the world in their most concentrated form, like powder, making it easier and lost costly because then we wouldn’t be shipping all that extra water.

This is why we need to be able to make solutions of any concentration from a more concentrated source.

The moles of the solute is always constant.

The concentration is based on the amount of water present.

MOLES OF SOLUTE BEFORE  =  MOLES OF SOLUTE AFTER

or

M1L1  =  M2L2

Where:

M = Moles

L = Litres

Eg.  15.0mL of 0.70M KCl  solution is diluted to a final volume of 150.0mL. What is the new concentration?

M1 =  0.70M

L1  =  15.0mL

M2 = ?

L2  = 150.0mL

M1L1  =  M2L2

0.70M  x 15.0mL = M2  x 150.0mL

0.70M x 15.0mL  =   M2

150.0mL          .

0.070M  =  M2

Eg.   A 0.275M solution is concentrated by evaporating the a reduced volume of 250.0mL and a molarity of 0.720M. What is the original volume?

M1 =  0.275M

L1  =  ?

M2 = 0.720M

L2  = 250.0mL

M1L1  =  M2L2

0.275M  x  L1 = 0.720M  x  250.0mL

L1  =  0.720M  x  250.0mL

       0.275M

L1  =  912mL

By:  JZ

molar concentration/molarity

Molar Concentration or molarity is the #of moles  of solute dissolved in a 1 L of solution.
- represented by M and it has the units of "mols/L."
The formula of Molarity = moles of solute (mol)
                                         volume of solution (L)
 M = mol/L.
 mol = M x L and L = mol/M are ways to find the mol and volume.


1) Calculate molar concentration that has a solution of 0.620 moles of CaCl2 in 1.7 L of solution.
2)Calculate the number of grams of sodium hydroxide in 3200mL of a 1.2 M KF solution.
3) Calculate the volume of L of 0.780 M NaCl solution that contains 55.21 g NaCl.


Answers:
1) M =0.620mol/ 1.7L 
=0.36(remember your sigfigs) 

2) 3200ml = 3.2 L
1.2M x 3.20L= 3.84 mols
convert mols to grams -------> 3.84 mols x 58.1g   = 223.104g--------------->220g
                                                                      1 mol
3) MM of NaCl = 58.5 g/mol
    55.21 g x 1 mol / 58.5 g
    = 0.944
L solution = 9.44444 moles of NaCl / 0.780
                = 12.108L




Post: JN 

bobby with snow :)