chemistry 10

• a molecule is two or more atoms chemically bonded together
• a synthesis reaction is when two elements combine to form one compound
• what is a decomposition reaction? a reaction in which a compound is broken down into simpler substances
• the three types of chemical reactions that can occur between compounds are synthesis, decomposition, and single displacement (sometimes combustion)
• A balanced equation has equal numbers of atoms on both sides of the arrow.
• Chemical equations show what happens during a chemical change.
• In a chemical equation, the reactants are written on the left-hand side of the arrow and the products are written on the right-hand side of the arrow.
• In a chemical equation, the coefficients tell us how many molecules or formula units of each substance take part in the reaction.
• When we write a chemical equation, we use symbols instead of words to represent the different substances involved.
• To balance an equation, we need to adjust the coefficients so that there are equal numbers of atoms on both sides of the equation.
• When we write an unbalanced equation, it means there aren't enough atoms to make everything balance out.
• The law of conservation of mass states that matter cannot be created or destroyed, only changed from one form to another.
• decomposition reaction: a chemical reaction in which a compound is broken down
• synthesis reaction: a reaction in which two or more molecules combine to form a new molecule
• single replacement: a single atom is replaced by another atom
• double replacement: when two atoms get replaced
• Decomposition: AB --> A+B
• synthesis: A + B --> AB
• Single replacement: AB+C = AC + B
• Double replacement: AB + CD --> AD + CB
• An ionic bond is a attraction between a metal and non-metal
• In an ionic bond, the electrons are transferred from the metal to the non-metal.
• A cation is a positively charged ion (metal ion), and an anion is a negatively charged ion (non-metal ion).
• A covalent bond is when two or more non-metals share electrons to form a molecule.
• Covalent bonds are much stronger than ionic bonds
• Nomenclature of ionic bonds: Metal (cation) first, then non-metal (anion) ending in -ide

  1. LiF = Lithium FlourIDE

  Name polyatomic as is

  2. Na2SO4 = Sodium Sulfate
• Some transition metals may form more than one ion so we need to know which ones were talking about.

  Use roman numerals to distinguish different states:

  1. FeCl2 = Iron (II) Chloride
  2. FeCl3 = Iron (III) Chloride
• Roman numerals 1-6: I , II , III , IV , V , VI
• Name formula, Aluminum Sulfate = Al2S3
• Name ReF4 = Rhenium (IV) Fluoride

  • because F has one arm which means Re needs to be IV (4)
• Nomenclature of covalent bonds: use prefixes to indicate the number of atoms bonded in each compound

  1. N2O3 = DInitrogen TRIoxide
  2. CO2 = Carbon DIoxide

  Note: ignore "mono" if it is in the first name (so carbon dioxide is not monocarbon....)
• Formula writing: use subscripts to indicate number of atoms present

  1. Diphosphorus hexoxide = P2O6
  2. Dinitrogen pentasulphide = N2S5
• Iron (III) oxide is an ionic bond
• Carbon tetrachloride is a covalent bond
• Mg3(PO4)2 is an ionic bond
• CCl4 is a covalent bond
• valence electrons are the outermost shell -determine the reaction

  • ones being traded in ionic compounds and shared in covalent compounds
• 1. Draw aluminum atom vs aluminum ion
  2. Draw oxygen atom vs oxygen ion
• Balance and name the reaction:

  Aluminum bromide plus chlorine yields aluminum chloride and bromide

  • 2AlBr3 + 3Cl2 -> 2AlCl3 + 3Br2
  • Single replacement reaction
• Balance: AgNO3 + KCl -> AgCl + KNO3

  1. How would you say this?

  Silver nitrate + potassium chloride yields silver chlorate + potassium nitrate