Chemical Reactions:

Changes in matter involve the arrangement and/or reorganizations of atoms and/or the transfer of electrons.

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Synthesis

A + B --> AB

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Decomposition

AB--> A + B

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Single Displacement

AB + C--> CB + A

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Double Displacement

AB + CD --> AD + CB

Remember, in order for this to happen something MUST come out of solution (HOH, gas, ppt.)

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Combustion

CH₄ + O₂ --> CO₂ +2H₂O

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Acid-Base Neutralization

HA + BOH--> HOH + BA

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Redox

A + + e-  à A    (reduction)

B  à  B + e-      (oxidation)

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Balanced Equations

Complete  Molecular:

AgNO3 (aq) + KCl(aq)-->AgCl(s) + KNO3 (aq)

Complete Ionic :

Ag+(aq) + NO3-(aq) + K+(aq) + Cl-(aq)-->

AgCl(s) + K+(aq) + NO3-(aq)

Net Ionic :

Ag+(aq) + Cl-(aq)-->  AgCl(s)

Spectator ions should not be included in your balanced equations.

Remember, the point of a Net Ionic Reaction is to show only those ions that are involved in the reaction.  Chemists are able to substitute reactants containing the same species to create the intended product.

You only need to memorize that compounds with nitrate, ammonium, halides and alkali metals are soluble.

Making Predictions

Solid copper carbonate is heated strongly:

CuCO3 (s) -->CuO (s)  + CO2 (g)

What evidence of a chemical change would be observed with this reaction?

One would observe a color change and evolution of a gas

What is the percent yield of CO2 if you had originally heated 10.0g CuCO3  and captured 3.2g CO2 ?

Step 1: Find the Theoretical Yeild

10.0g CuCO3 x(1mol/123.555g) x (1mol CO2 /1 molCuCO3 ) X 44.01gCO2/mol = 3.562 gCO2

Step 2: Find Percent Yield

(3.2 g / 3.562 g) * 100 = 89.8 %    90% with correct sig figs

How could you improve your percent yield?

-reheat the solid, to see if there is any further mass loss

-make sure you have pure CuCO3