AP Chemistry Unit 4

2Mg(s) + O2 (g) —> 2MgO

Synthesis Reaction

HgO (s) + Heat —> Hg(s) + ½ O2 (g)

Decomposition Reaction

HCl (aq) + NaOH (aq) —> NaCl (aq) + H2O (l)

Acid-Base Reaction

Cu⁺² (aq) + 2e^- —> Cu(s)

Oxidation-Reduction Reaction

C4H10 + 13/2 O2 —> 4CO2 + 5H2O

Hydrocarbon Combustion Reaction

CO3^2- (aq) + Mg²⁺(aq) —> MgCO3 (s)

Precipitation Reaction

Soluble SNAP ions

• Sodium

• Potassium

• Ammonium

• Nitrate

When balancing a chemical equation what should you start with?

The most complicated looking compound

Steps to Stoichimetry

1. Convert whatever quantities you are given into moles

2. Determine the limiting Reactant

3. Use Balanced chemical equation to determine the moles of product the limiting reactant can generate

4. Do further Unit conversions

How to determine the limiting Reactant

1. Divide the moles of each by its coefficient in the balance equation. This gives us the ratio so the smaller one is the limiting reactant

2. Using the balanced chemical equation, determine the maximum moles of product each of the reactants can generate

Percent Error and Yield

• Percent Error (experimental value - expected value) / expected value x 100

• Percent Yield (Experimental / Expected) x 100

How to determine the reactants in a Combustion Reaction

1. convert grams to moles

2. the moles are the ratio of what the original reaction was

Gravimetric Analysis can be used to (blank)

determine the identity of an unknown sample

Oxidation States Rules

1. Any neutral atom not bonding to any other element is 0

2. Monoatomic (charged particle) ions have an oxidation state equal to the charge on the ion

3. In compounds oxygen is -2 (Exception in hydrogen perxoide it is -1)

4. When bonded to a nonmental Hydrogen is +1 but in metals it is -1

5. The most electronegative element in a compound will take on the state equal to its most common charge

6. combined oxidation states must add up to 0

OIL RIG

• oxidation is loss of electrons

• reduction is gain of electrons

Titration experiments can help establish (blank)

the identity and concentration of unknown solutions called analytes

The Titrant is the (blank)

known concentration and identity and is carefully added to the analyte

The tipping point is called the (blank)

equivalence point

Conjugate pairs are two species whose formulas only differ by (blank)

one proton

The species with the extra proton can donate it and is called the (blank)

conjugate acid

The species lacking a proton can accept one is called the (blank)

conjugate base)

Water is (blank) meaning it can act as either an acid or a base

amphoteric