predicting products (aka: soap opera chemistry). why are we learning this? chemistry standard #3a:...
TRANSCRIPT
Predicting Products
(AKA: Soap opera Chemistry)
Why are we learning this?
Chemistry Standard #3A:
Students know how to describe and balance chemical reactions
Five types of reactions:1.Synthesis (Combination)2.Decomposition3.Single Replacement4.Double Replacement5.Combustion
1. Synthesis (or Combination)
2 or more substances react to form 1 product
A + B AB
The soap opera begins . . .
+
Rob + Sally Rob/Sally
Demo #1: Synthesis Reaction
Mg(s) + O2(g) MgO(s)
Remember to balance the equation!
2 2
2. Decomposition
A compound breaks down into simpler substances.
-requires heat, light, electricity, or a chemical catalyst
AB A + B
Drama with Rob and Sally . . .
+ Sally
+
Rob/Sally Rob
Demo #2: Decomposition Reaction
_C12H22O11+_ KNO3(s)
Remember to balance the equation!
__CO2 (g) + __H2 O(g)
3. Single Replacement Reaction
Atoms in single element replace atoms in compounds
• Can be cationic or anionic . . .– A metal replaces the cation in the compound– A nonmetal replaces the anion in the compound
Cationic SR: A is a metal element, B is cation (+)
A +BC AC + B Anionic SR: C is a non-metal element, D is anion (-)
C + BD BC + D
How can you know if one metal will displace another?
reactive metal replaces any below it.
Will this React? Mg + ZnCl2
Will this React? Mg + CaCl2
Li
K
Ca
Na
Mg
Al
Zn
…
MgCl2 + Zn
YES !
NR
Along comes Brian . . .
Brian
+ +
+ Rob/Sally Brian/Sally + Rob
Demo #3: Single Replacement Reaction
Cu(s) + AgNO3(aq) Ag(s)+ CuNO3(aq)
Cu(s) + AgNO3(aq) Ag(s) + CuNO3(aq)
Mg(s) + CuNO3(aq) Cu(s) + Mg(NO3)(aq)
Grey blue aqueous reddish clear aqueous
metal solution metal solution
4. Double Replacement Reaction
Compounds exchange cations
AB + CD CB + AD
Drama at the prom . . .
+ +
+ Brian/Sally Rob/Pam Brian/Pam + Rob/Sally
Demo #5: Double Replacement Reaction
Cu(NO3)2(aq)+ NaOH(aq) Cu(OH)2(aq) + NaNO3
Remember to balance the equation!
2 2
An element/compound reacts with O2 producing heat &/or light.
Example: Mg(s) + O2(g) MgO(s)
with hydrocarbons yielding CO2 and H2O
Example: C3H8 + O2 CO2 + H2O
5. Combustion
The Soap opera Ends
Brian + O2 CO2 + H2O
Oh No!(A hydrocarbon)
Demo#6: Combustion
__C3H7OH + __O2 __CO2 + __ H2O
Propanol
Remember to balance the equation!
Six types of chemical reaction
CombustionSynthesisDecompositionSingle DisplacementDouble DisplacementAcid-base