1. Li+, Na+, K+, NH4+ (primary rule)
Soluble
Insoluble (Precipitates)
Li+, Na+, K+, NH4+ (primary rule)
NO3-, C2H3O2-, ClO3-
Cl-, Br-, I-
Ag+, Hg22+ , Pb2+
SO42-
Ba2+, Ca2+, Sr2+
CO32-, O2-, PO43-
OH-
Ba2+, Ca2+, Sr2+, Mg2+
S2-
Chemistry – Feb 3, 2017
P3 Challenge –
Determine if each of the following compounds are soluble (aq) or insoluble (s):
1) CdCl2
2) ZnO
3) Na2S
Today’s Objective –
Driving forces for reactions, pt 2
Get out Net ionic equations page and
acid/base section for HMK check

2. Chemistry – Feb 2, 2017 Objective – Driving forces Assignment:
Driving forces worksheet
Agenda
Homework Review
Acids and bases
Neutralization reactions
Gas forming reactions
Electron Transfer

3. Driving Force
We can write many kinds of reactions on paper, but for them to actually occur, there must be some kind of driving force. Otherwise a simple mixture will happen with no reaction.
Driving Forces:
Formation of a solid
Formation of water
Formation of a gas
Transfer of electrons
Determines a second classification
Note: Any given reaction may have more than one driving force. But if it has none, it will not happen.

4. 2) Formation of water: Acids and Bases
Acids react with bases to form water and an ionic salt.
Formation of water is a driving force.
Recall acids are molecular compounds that dissociate to form ions.
6 acids dissociate completely and are called strong acids. (memory item)
HCl HBr HI
HNO3 H2SO4 HClO4
All other acids are weak acids that do not split into ions.
Hydroxides of alkali and alkaline earth metals are strong bases.
Ex: HC2H3O2 (aq) + NaOH(aq)  H2O (l) + NaC2H3O2 (aq)

5. 3) Formation of a gas If a gas is produced, it will the driving force.
Acid base reactions, decomposition reactions, and combustions often form gases.
Common gases are CO2, NO2, SO2, NH3, H2S, H2, O2, N2, F2, Cl2
If a product is a gas, then gas formation is a driving force.
Ex: K2CO3 (s)  K2O (s) + CO2(g)

6. 4) Transfer of electrons: Oxidation-Reduction
How to identify a redox reaction
Is there an atom that is an element on one side and in a compound on the other side? (Single Replacement reaction)
Is there an element that has a different charge ion on both sides? (Many synthesis and decomposition reactions. Also combustion.)
Transfer of electrons is a driving force. Elements are driven to complete octets.
Note: All combustion reactions are driven by electron transfer, but may also be gas forming.

7. Activity Series
For single replacement reactions, the determining factor is the place of the two metals in the activity series.
In general, a higher metal can displace any of the metals which are lower in the activity series:
Ex: Cu + AgNO3  Cu(NO3) Ag
Ex: Cu + Fe(NO3)3  Cu (NO3)2 + Fe
Ex: Zn + Fe(NO3)3  Zn (NO3)2 + Fe

8. Reactivity Series for Halogens
In general, a halogen can displace any of the halogens which are lower in the activity series for halogens.
Notice that the activity series of halogens is just their order within the periodic table.
Ex: F NaBr  2 NaF + Br2
Ex: Br NaCl  2 NaBr + Cl2

9. Exit Slip - Homework Exit Slip: Determine the net ionic equation for:
NiCl2 (aq) KOH (aq)  Ni(OH)2 (s) KCl (aq)
What’s Due? (Pending assignments to complete.)
Start the Driving Forces Worksheet (Pages 2-3)
What’s Next? (How to prepare for the next day)
Read p473, p , p , p