Reactions and Equations

Chemical Reaction - One or more substances change into one or more new substances

Represents with symbols and formulas

The identities and relative amounts of the reactants and products in a chemical reaction

Reactants-Left side of an equation- what starts the reaction

Products- right side of an equation- what a rxn ends with

1. Production of heat/light

2. Production of gas3. Formation of a

precipitate Precipitate: a

solid produced- separates from a solution

4. Color Change

Word equation- uses words Formula equation- formulas and

symbols Complete Ionic Formula- shows soluble

substances in their dissociate form Net Ionic equation- removes the

spectator ions which are present on both sides of the equation.spectator ions = IONS that are exactly the same on both sides

- yields- solidg - gasaq- aqueous- solid producedheat as a catalyst

l - liquid - gas produced reversible reaction

Reversible reaction- products can reform reactants

Catalyst- “speeds” up a reaction- lowers the activation energy

1. Write the correct formulas2. Use coefficients to balance (big # in

front)3. Check each individual element4. Reduce coefficients if needed

1. Synthesis- (combination) two or more substances combine to produce a more complex substance.

x + y xy 2. Decomposition- A substance breaks down into two or

more simpler substances.xy x + y

3. Single Replacement (displacement)- a single element replaces a similar element in a compound

metal will replace metal nonmetal will replace nonmetal

x + ay xy + a4. Double Replacement (double displacement)- positive

ion exchange xy + ab ay + xb

5. Combustion- rapid reaction that involves O2

Organic + O2 CO2 + H2O

Solute- small part- is dissolved

Solvent- large part- does dissolving

Spectator ions- present in solution on both sides of the yield

% Composition – Element x100Compound

Empirical Formula – Lowest whole number ration of elements in a compound.

Empirical Formula From % Composition- % → grams → moles→ divide my lowest number of moles = Ratio! :D

Molecular Formula : From empirical Molecular Mass x Empirical Formula

Empirical Mass

Hydrates: Crystals that contain water in crystal.