# Key Equations

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### Fundamentals

 1 Acid + active metal Acid + Active metal → Salt + Hydrogen eg. Hydrochloric acid + magnesium → Magnesiium chloride + hydrogen gas 2HCl(aq) + Mg(s) → MgCl2(aq) + H2(g) All active metals are above 0.00 V (the hydrogen half cell) in the standard reduction table. Eg. Zn, Mg, Fe, etc. 2 Acid + Carbonate Acid + Carbonate → Salt + Water + Carbon dioxide Eg. Ethanoic acid acid + Sodium hydrogen carbonate → sodium ethanoate + water + carbon dioxide CH3COOH(aq) + NaHCO3(aq) → CH3COO-Na+(aq) + H2O(l) + CO2(g) 3 Acid + Alkali Acid + Alkali → Salt + Water eg. Sulfuric acid + potassium hydroxide → potassium sulfate + water    H2SO4(aq) + 2KOH(aq) → K2SO4(aq) + 2H2O(l) Note: All neutralisation equations are exothermic in nature as the net ionic reaction is the same. H+(aq) + OH-(aq) → H2O(l) ∆H < 0

### 9.2 Equations

 1 Fermentation equation C6H12O6(aq) → 2C2H5OH(aq) + 2CO2(g) 2 Combustion of ethanol C2H5OH(aq) + 3O2(g) → 2CO2(g)+ 3H2O(l) 3 The addition of bromine to cyclohexene 4 The addition polymerisation of a) polyethylene b) polyvinyl chloride c) polystyrene nCH2=CH2 (-CH2-CH2-)n ethylene polyethylene nCH2=CHCl (-CH2-CHCl-)n vinyl chloride polyvinyl chloride   nCH2=CHC6H5 (-CH2-CHC6H5-)n styrene polystyrene 5 Condensation of glucose to cellulose n(C6H12O6) → (-C6H10O5-)n + (n-1)H2O(l) glucose → celluose + water Cellulose is made up of repeating glucose units. Note: The beta 1,4 glycosidic bond (oxygen atom joining the monomers) alternates with the CH2OH side group 6 Ethanol to Ethylene and Ethylene to Ethanol Remember the catalyst for each 7 Lead acid battery Anode: Oxidation: Pb(s) + SO42-(aq) → PbSO4(s) + 2e- 0.36 V Cathode: Reduction: PbO2(s) + 4H+(aq) + SO42-(aq) + 2e- → PbSO4(s) + 2H2O(l) 1.69 V   Electrolyte. The 4 to 6 M H2SO4 (The sulfuric acid keeps the concentration of Pb2+ ions low by forming insoluble lead sulfate, which adheres to the electrodes. Since the electrodes are intact the battery is rechargeable.) 8 Lithium cell Anode: Li → Li+ + e- Cathode: ½ I2 + e- → I- Electrolyte: Solid sate. The non aqueous electrolyte is a conducting polymer containing Li+I- formed between the anode and the cathode. 9 Describe how commercial radioisotopes are produced Include equations Commerical radioisotope can be produced in a) nuclear fission reactors by bombarding target nuclei with neutrons. Eg. The production of Cobalt-60, + → Nuclear fission reactors produce radioisotopes that are ‘rich’ in neutrons. and b) particle accelerators by bombarding target nuclei with charged particles(eg. protons & ions). Eg. The production of carbon-11 in a cyclotron, + → Particle accelerators produce radioisotopes that are deficient in neutrons.

### 9.3 Equations

1.

Acid rain formation from sulfur and nitrogen oxides
 Sulfur oxides Nitrogen oxides SO2(g) + H2O(l) ==> H2SO3(aq) Sulfurous acid SO2(g) + ½O2(g) =particulates> SO3(g) SO3(g) + H2O(l) ==> H2SO4(aq) Sulfuric acid NO(g) + ½O2(g) ==> NO2(g) brown H2O(l) + 2NO2(g) ==> HNO3(aq) + HNO2(g) Mixture of nitric and nitrous acid

2.

Strong and weak acids

All 0.1 M conetration

Strong acids completely ionise producing a lower pH

HCl(aq) ==> H+(aq) + Cl-(aq), pH =1

H2SO4(aq) ==> 2H+(aq) + SO42-(aq), pH = 0.7

Sulfuric acid is diprotic, producing more H+ ions than HCl and therefore has a lower pH

Weak acids only partially ionise producing a higher pH

CH3COOH(aq) <==> CH3COO-(aq) + H+(aq), pH = 3

Citric acid <==> citrate ion + H+(aq) , pH = 4 (Ionises less than acetic acid producing a higher pH)

3.

HCO3- reaction with and acid and a base

Acting as an acid (H+ donor): HCO3-(aq) + OH-(aq) <==> CO32-(aq) + H2O(l)

Acting as a base(H+ acceptor): HCO3-(aq) + H3O+(aq) <==> H2CO3( aq) + H2O(l)

4.

9.4 Haber process

What catalyst is used? How does it work?

N2(g) + 3H2(g) <==> 2NH3(g) ∆H = -92kJ

A finely ground iron catalyst, Fe3O4, with a large surface area, is used in the Haber process.

The gaseous nitrogen and hydrogen molecules are adsorbed and rearranged forming the ammonia molecules. By lowering the activation energy, a catalyst enables a more rapid reaction at lower temperatures.

5.

Esterification

Esterification is a condensation reaction: Alcohol + organic acid --> Ester (alkyl alknoate) + Water When you are given the structure of an ester first identify the acidic component by circling it. The acidic component is the last part of the ester name. eg. methanoate, ehtanoate, propanoate, butanoate, etc.

Name the following ester. What was it made from? 