chapter8_egmw

Chemical Equations: Represents, with symbols and formulas, the molar amounts of products and reactants in a chemical equation. ex: A (s) + B (g) → C (aq) + D (g) A and B are the products. C and D are the reactants.

(S)- Solid (L)- Liquid (Aq)- Aqueas (dissolved in water) (G)- Gas A chemical reaction is when one or more substances are changed into one or more diferent substances. Signs of a chemical reaction are:
 * Chemical properties change
 * Color change
 * Forms a precipitate (liquid + liquid = solid)
 * Change in temperature
 * Gas released
 * Light or sound produced

BrINClHOF- all of these elements (Br, I, N, Cl, H, O, F) will exist as X 2 ** Balanced equations tell the balanced ratio of products and reactants. The number of moles of one element must be the same on both sides of the reaction.
 * Equations must be balanced!

Ex: Methane and oxygen yield carbon dioxide and water.

Equation: CH 4 + O 2 → CO 2 + H 2 O

Balanced: CH 4 + 2 O 2 → CO 2 + 2 H 2 O

**Five Types of Chemical Reactions** A and X are either elements or compounds but AX has to be a compound because of the two elements. Reactions of elements with oxygen and sulfur. When an element is combined with oxygen it produces an oxide. Most metals are able to form oxides. Most elements will act similarly with sulfur and will produce sulfides. Non metals can also form oxides but when they react the product is a dioxide. Reactions with metals and halogens. the halogens can react with most metals to from either ionic or covalent compounds. Group one and two will react to form ionic compounds. Reactions with oxides. Oxides that are made with an active metal will react with water form a metal hydroxide. //ex. 2Mg + O 2 → 2MgO//
 * Synthesis: ** A + B → AB

One compound is broken apart by a reaction to form at least two simpler substances. As in the synthesis AX must be a compound but A and X can be either element or compounds. Most decomposition reactions will only occur if energy is added. The most common ways of adding energy are by heat and electricity. When you use electricity to break down a substance it is called electrolysis. Of all the decomposition reactions the most simple one is the decomposition of a binary compound into the elements that it is made of. Oxides that are less active must be heated to decompose. When you heat a metal carbonate it will always break down into a metal oxide and carbon dioxide gas. But when Metal Hydroxide is heated the result is always at least one metal oxide and water. Metal chlorate decomposes and creates a Metal Chloride and oxygen. Some acids will decompose to form a nonmetal oxide and water. //ex. 2KlO 3 → 2KCl + 3O 2 //
 * Decomposition: **AB → A + B

reactions happen when one element replaces a similar element in a compound. Not a lot of energy is required in a single displacement reaction. Displacement of a metal in a compound by a different metal. In this reaction the more active metal is placed in the less active aqueous solution the solid metal will change its place with the metal in the solution. Displacement of hydrogen in water by a metal. Metals that have an extremely high activity will react with water to form a metal hydroxide and hydrogen. Less active metals will react to steam and will create a metal oxide and a hydrogen gas. Displacement of hydrogen in an acid by a metal. some acids will react with an active metal to produce an metal compound and hydrogen. Displacement of Halogens is where one halogen can replace a different halogen in a compound. The halogens can each replace any halogen below it, but not above it. This is because the halogen group is most reactive at the top of the periodic table. //ex. Cu + AgNO 3 → Ag + CuNO 3 *Make sure charges balance//
 * Single Replacement: ** A + BC → AC + B (A and B have to be metals for the reaction for work)

reactions are where ions of both compounds change places when they are in an aqueous solution. ( AX+BY --> AY+ BX) One of the compounds will be a gas and be released from the solution and the other will be dissolved in the solution. The precipitate is formed when the cation of one compound and the anion of the other react and form a insoluble compound. Sometimes a stable compound like water can be formed. //ex. Cu(NO 3 ) + 2NaOH → Cu(OH 2 ) + 2NaNO//
 * Double Replacement: **AB + CD → AD + CB (Metals are always listed first, no left out ions)

A + O 2 → CO 2 + H 2 O Hydrocarbon Combustion (H + C) CH 4 + 20 2 → CO 2 + 2H 2 0
 * Combustion:** when a substance and oxygen combine and create enough energy that it produces light and heat. The burning of fossil fuels is a combustion reaction.

Non-Hydrocarbon Combustion (combustion of synthesis) 2Ca + O 2 → CO 2 + 2H 2 O

** Activity Series: ** An activity series is a list of elements which are arranged in the order of the elements willingness to form a certain reaction. They are used to tell whether a reaction can take place or not. The order of the activates series is typically based on their single-displacement reactions. The element with the most activity goes at the top of the list. It is able to replace every element with a lower activity in a single-displacement reaction. Once the elements get farther down, they can only replace the less active elements but not the ones above it.

Hints
With metals a greater activity will mean that it will be easier to lose an electron so it can be a positive ion. Nonmetals the more activity means that they can more easily gain electrons to make them negative ions.

** Review: ** Balance the following equations:
 * 1) Li 2 O + H 2 O → LiOH
 * 2) H 3 PO 3 → H 3 PO 4 + PH 3
 * 3) SiC + Cl 2 → SiCl 4 + C
 * 4) Al + SnCl 4 → Sn + AlCl 3
 * 5) C 2 H 6 O + O 2 → CO + H 2 O

Identify the type of chemical reaction:
 * 1) CaCO 3 → CaO + CO 2
 * 2) C 3 H 8 + 5O 2 → 3CO 2 + 4H 2 O
 * 3) N 2 + 3H 2 → 2NH 3
 * 4) Fe(NO 3 ) 3 + 3NaOH → Fe(OH) 3 + 3NaNO 3
 * 5) 2Li + MgCl 2 → Mg + 2LiCl


 * Answers to Review: **
 * 1) Li 2 O + H 2 O → 2 LiOH
 * 2) 4 H 3 PO 3 → 3 H 3 PO 4 + PH 3
 * 3) SiC + 2 Cl 2 → SiCl 4 + C
 * 4) 4 Al + 3 SnCl 4 → 3 Sn + 4 AlCl 3
 * 5) C 2 H 6 O + O 2 → 2 CO + 3 H 2 O<span style="color: rgb(255,0,0);">


 * 1) Decomposition
 * 2) Combustion
 * 3) Synthesis
 * 4) Double Replacement
 * 5) Single Replacement

**Megan Henney and Keenan Robertson**