1. Unit I: CHEMICAL REACTIONS
I.5. Using Chemical Word Equations

2. Words  Balanced Chemical Equations
Need to Remember the difference between ionic and covalent (molecular)
If Ionic – use charges
If Covalent – use prefixes

3. Words  Balanced Chemical Equations
Diatomics AGAIN!!!
N2, O2, F2, Cl2, Br2, I2 and H2
In a balanced chemical equation these elements are ALWAYS found in their diatomic or molecular form!!!!!!!!!!

4. Phases
Sometimes a chemical reaction will also show the phases in which the reactants and products exist
(s) – solid {crystals, powder, precipitate}
(l) – liquid
(g) – gas
(aq) – aqueous (water solution)

5. Words  Balanced Chemical Equations
General Rules
Write the formulas of the compounds
Don’t forget your diatomics O must be O2
Add phases (s), (l), (g), (aq) if indicated
Balance your chemical equations as before

6. Precipitate
A precipitate is used to refer to a solid formed when two liquid or aqueous solutions react.

7. Precipitate

8. Example 1
aluminum chloride is mixed with potassium carbonate and aluminum carbonate and potassium chloride are formed. Write a balanced equation.

9. Example 2
Aluminum metal reacts violently with bromine to produce aluminum bromide. Write a balance equation.

10. Example 3
Sodium reacts quickly with water to produce hydrogen gas and sodium hydroxide

11. Example 4
Nitrogen monoxide reacts with oxygen to produce nitrogen dioxide.

12. Example 5
Magnesium sulphate heptahydrate decomposes to form water and magnesium sulphate.

13. Acid Review Name Formula hydrochloric acid HCl nitric acid HNO3
sulphuric acid
H2SO4
acetic acid
CH3COOH
phosphoric acid
H3PO4

14. Hebden
Do Exercises 57 (a-e), 58, 59, 60 and 61 on p {include phases where indicated}
Do problem set 2 on page 6 in your student notebook
Do Hand-In Assignment #7 – Chemical Equations