Chemical Change: The change of substances into other substances through a reorganization of the atoms. Chemical Change: The change of substances into other substances through a reorganization of the atoms. Copyright © 2010 Ryan P. Murphy

Combustion: When oxygen combines with another compound to form water and carbon dioxide. Combustion: When oxygen combines with another compound to form water and carbon dioxide. CH 4 (g) + 2O 2 (g) → CO 2 (g) + 2 H 2 O(g) Methane oxygen Carbon Dioxide Water

Synthesis Reaction: When two or more simple compounds combine to form a more complicated one. A + B = AB Synthesis Reaction: When two or more simple compounds combine to form a more complicated one. A + B = AB Zn + 2 HCl → ZnCl 2 + H 2 (g) Zn + 2 HCl → ZnCl 2 + H 2 (g) Copyright © 2010 Ryan P. Murphy

Decomposition Reaction: A complex molecule breaks down to make simpler ones. Opposite of Synthesis Reaction. AB  A + B 2 H 2 O ---> 2 H 2 + O 2 (Electrolysis of Water) Copyright © 2010 Ryan P. Murphy

Single Displacement: When one element trades places with another element in a compound. BC + A  AC + B Single Displacement: When one element trades places with another element in a compound. BC + A  AC + B

Double Displacement: When two different molecules switch places, forming two entirely different compounds. AB + CD  AD + CB AgNO 3 + NaCl → AgCl + NaNO 3 AgNO 3 + NaCl → AgCl + NaNO 3

Acid / Base: When an acid and base react with each other. Acid / Base: When an acid and base react with each other.

Acid: a substance which when added to water produces hydrogen ions [H + ]. Acid: a substance which when added to water produces hydrogen ions [H + ]. React with zinc, magnesium, or aluminum and form hydrogen (H 2(g) ) React with zinc, magnesium, or aluminum and form hydrogen (H 2(g) ) React with compounds containing CO 3 2- and form carbon dioxide and water React with compounds containing CO 3 2- and form carbon dioxide and water Turn litmus red Turn litmus red Taste sour (lemons contain citric acid, for example) Taste sour (lemons contain citric acid, for example) Tasting Acids in the lab would be unsafe. Tasting Acids in the lab would be unsafe.

pH scale

New Area of Focus: Subscripts and Coefficients New Area of Focus: Subscripts and Coefficients Coefficients tell us the number of molecules. Subscripts tell us how many atoms or ions there are within a compound. Coefficients of 1 are never written - they are understood. Subscripts of 1 are never written – they’re understood

Balancing Chemical Equations. Balancing Chemical Equations.

Remember the Law Conservation of Mass: Matter cannot be created or destroyed. That means we need to have the same amount of chemicals on each side of the . Remember the Law Conservation of Mass: Matter cannot be created or destroyed. That means we need to have the same amount of chemicals on each side of the . For this reason, put a square around the chemical formulas. For this reason, put a square around the chemical formulas. Example Example

A way to start off the process is to create an inventory of your chemicals. A way to start off the process is to create an inventory of your chemicals.

This is a balanced equation.

It should work most of the time although it can be very tricky. Always keep an inventory chart or it will get all messed up. Try to balance… BOXES! __CH4 + __O2 --> __CO2 + __H2O C H O

Answer: See if this is right? Answer: Yes, A balanced equation __CH4 + __O2 --> __CO2 + __H2O 1 CH O 2 --> 1 CO H 2 O C H O 1 4 4

Try Again __CH4 + __O2 --> __CO2 + __H2O ___ NaCl + __ BeF 2 --> __ NaF +__ BeCl 2 Na Cl Be F

__CH4 + __O2 --> __CO2 + __H2O 2 NaCl + 1 BeF 2 --> 2 NaF + 1 BeCl 2 Na Cl Be F

__CH4 + __O2 --> __CO2 + __H2O __Mg + __Mn 2 O 3 --> __MgO + __Mn Mg Mn O F

Answer: See if this right? This is a balanced equation. __CH4 + __O2 --> __CO2 + __H2O 3 Mg + 1 Mn 2 O 3 --> 3 MgO + 2 Mn Mg Mn O F

Exothermic Reactions: Chemical reactions that releases energy in the form of heat, light, or sound. The products contain less energy than the reactants Heat is lost to the surroundings.

Endothermic reactions: These reactions absorb energy in order to proceed. The products contain more energy than the reactants, heat is taken in or absorbed from the surroundings. A temperature drop is measured during the reaction.