1. Chemical Equations Writing, Balancing and Predicting Products

2. LAYOUT OF EQUATIONS Chemical equations are short hand ways of detailing what happens during a reaction The general form of and equation is: [reactants] → [products] Hydrogen + oxygen → water [Products][Reactants] “Rearrange to form”

3. WORD, FORMULA AND BALANCED Word: proper chemical names sodium + water → sodium hydroxide + hydrogen Formula: balanced formula of chemical + states Na + H 2 O → NaOH + H 2 Balanced: equal number of each element on each side 2 Na + 2 H 2 O → 2 NaOH + H 2

4. WORD EQUATIONS Water and oxygen are products of the decomposition of hydrogen peroxide (H 2 O 2 ). 1. Identify the chemicals Water, oxygen and hydrogen peroxide 2. Identify the chemicals as reactants or products Reactants: Hydrogen Peroxide Products: water and oxygen 3. Place arrow between reactants and products Hydrogen peroxide → water and oxygen

5. FORMULA EQUATIONS Water and oxygen are products of the decomposition of liquid hydrogen peroxide (H 2 O 2 ) at room temperature. WE:Hydrogen peroxide → water and oxygen 1.Replace the words with the chemical formulas* (You may also add states if known) H 2 O 2 (l) → H 2 O (l) + O 2 (g) *For more complex formulas you may need to refer to your data sheet, work out ions and criss- cross eg: iron(III) oxide

6. BALANCED EQUATIONS “Matter is neither created or destroyed” simply re-arranged. Like a see-saw we need to make sure the same number of each atom is on each side to be balanced. 2 H 2 O 2 (l) → 2 H 2 O (l) + O 2 (g) AtomReactantsProducts H 2 4 O 3 4