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Chemistry

Chemical Reactions Year 12 Chemistry Students Must Know

A helpful list of essential chemical reactions that a Year 12 student should know.

Combustion of a Carbon Compound

Hydrocarbon + Oxygen → Carbon Dioxide Gas + Liquid Water

E.g. 2C8H18(l) + 25O2(g) → 16CO2(g) + 18H2O(l)

 

Metals with Acids


Metal + Acid → Salt + Hydrogen gas

E.G. Zn(s) + 2HCl(aq) → ZnCl2(aq) + H2(g)

 

Carbonates with Acids

Carbonate + Acid → Salt + Carbon Dioxide Gas + Liquid Water

E.g. Na2CO3(aq) + 2HCl(aq) → 2NaCl(aq) + CO2(g) + H2O(l)

 

Oxidation


Metal → Metal Ion + Electron/s

E.g. Cu(s) → Cu2+(aq) + 2e

 

Reduction

Metal Ion + Electron/s → Metal

E.g. Ag+(aq) + e → Ag(s)

 

Redox (Reduction-Oxidation Reactions)

This reaction involves the transfer of electron/s from one reactant to another. This thus results in both a reduction and oxidation reaction occurring. To obtain the redox reaction, you can either write the net ionic equation for a displacement reaction (option 1) or add reduction and oxidation reactions together (option 2).

E.g. OPTION 1:

Cu(s) + 2AgNO3(aq) → Cu(NO3)2(aq) + 2Ag(s)

Cu(s) + 2Ag+(aq) + 2NO3 → Cu2+(aq) + 2NO3 + 2Ag(s)

Cu(s) + 2Ag+(aq) + 2NO3 → Cu2+(aq) + 2NO3 + 2Ag(s)

Cu(s) + 2Ag+(aq) → Cu2+(aq) + 2Ag(s)

 

E.g. OPTION 2

NOTE: BOTH THE CONSERVATION OF MASS AND CHARGE MUST BE SHOWN IN YOUR EQUATION!

Cu(s) → Cu2+(aq) + 2e

                                    +

2Ag+(aq) + 2e → 2Ag(s)

__________________

Cu(s) + 2Ag+(aq) + 2e → Cu2+(aq) + 2e + 2Ag(s)

Cu(s) + 2Ag+(aq) + 2e → Cu2+(aq) + 2e + 2Ag(s)

Cu(s) + 2Ag+(aq) → Cu2+(aq) + 2Ag(s)

 

Lime Water Test (Lime Water and Carbon Dioxide)

Calcium hydroxide + Gaseous carbon dioxide  Solid calcium carbonate + liquid water

I.e. Ca(OH)2(aq) + CO2(g) → CaCO3(s) + H2O(l)


Hydrogenation

Alkene + Hydrogen → Alkane

E.g. C2H4(g) + H2(g) → C2H6(g)                                           Catalyst is Pt(s)

 

Bromination

Alkene + Bromine → Vicinal dibromide

E.g. C2H4(g) + Br2(g) → CH2BrCH2Br(g)

 

Chlorination

Alkene + Chlorine → Vicinal dichloride

E.g. C2H4(g) + H2(g) → CH2ClCH2Cl(g)

 

Hydrohalogenation

Alkene + HX → Alkyl halide

E.g. C2H4(g) + HBr(g) → CH3CH2Br(g)

 

Substitution with Bromine

Alkene + Bromine → Organobromine compound + Hydrogen bromide

E.g. C2H6(g) +Br2(l) → C2H5Br(l) +HBr(g)           

NOTE: This reaction requires the presence of UV light.                                    

 

Hydration

Alkene + Water → Alkanol

E.g. C2H4(g) + H2O(g) → CH3CH2OH(g)                             Catalyst is dilute H2SO4

 

Dehydration

Alkanol → Alkene + Water

E.g. CH3CH2OH(g) → C2H4(g) + H2O(g)                             Catalyst is concentrate H2SO4

 

Fermentation of Glucose

Aqueous Glucose → Ethanol + Carbon Dioxide Gas

I.e. C6H12O6(aq) → 2CH3CH2OH(aq) + 2CO2(g)                  Catalyst is zymase (found in yeast)

 

Alpha Decay

Beta Decay

Neutralisation

Acid + Base → Salt + Liquid Water

E.g. HCl(aq) + NaOH(aq) → NaCl(aq) + H2O(l)

 

Carbon Dioxide and Water

Aqueous carbon dioxide + Liquid water ↔ Carbonic Acid

I.e. CO2(aq) + H2O(l)  H2CO3(aq)

 

Formation of Sulfur Dioxide

Sulfur + Gaseous oxygen → Sulfur Dioxide

I.e. S(s) + O2(g) → SO2(g)

 

Formation of Sulfurous Acid

Gaseous sulfur dioxide + Liquid water → Sulfurous acid

I.e. SO2(g) + H2O(l)  H2SO3(aq)

 

Formation of Sulfur Trioxide

Gaseous sulfur dioxide + Gaseous oxygen → Sulfur trioxide

I.e. 2SO2(g) + O2(g) → 2SO3(g)

 

Formation of Sulfuric Acid

Gaseous sulfuric acid + Liquid Water → Sulfuric acid

I.e. SO3(g) + H2O(l) → H2SO4(aq)

 

Formation of Nitrogen Monoxide

Gaseous oxygen + Gaseous nitrogen → Gaseous nitrogen monoxide

I.e. O2(g) + N2(g) → 2NO(g)

 

Formation of Nitrogen Dioxide

Gaseous nitrogen monoxide + Gaseous oxygen → Gaseous nitrogen dioxide

I.e. 2NO(g)  + O2(g) → 2NO2(g)

 

Formation of Nitric Acid

Gaseous nitrogen dioxide + Liquid water → Nitric acid + Gaseous nitrogen monoxide

I.e. 3NO2(g) + H2O(l) → 2HNO3(aq) + NO(g)

 

Ionisation of an Acid in Water

Acid + Liquid Water → Hydronium Ion + Anion

E.g. HCl(aq) + H2O(l) → H3O+(aq) + Cl(aq)

E.g. H2SO4(aq) + H2O(l) → H3O+(aq) + HSO4(aq)

 

Esterification

Ethanoic acid reacts with ethanol in the presence of concentrated sulphuric acid as a catalyst to produce the ester, ethyl ethanoate. The reaction is slow and reversible. To reduce the chances of the reverse reaction happening, the ester is distilled off as soon as it is formed.

Alkanoic acid + Alcohol  Alkyl alkanoate + Water               (Catalyst: Concentrated sulfuric acid)

E.g. CH3COOH(aq) + CH3CH2OH(aq)  CH3COOCH2CH3(aq) + H2O(l)

 

Formation of Ozone

1. Gaseous oxygen + High energy UV → Oxygen free radical

I.e. O2(g) + UV → 2O.(g)

 

2. Gaseous oxygen + Oxygen free radical → Gaseous ozone

I.e. O2(g) + O.(g) → O3(g)

 

Destruction of Ozone

1. Photodissociation of CFC

E.g. CF2Cl2(g) + UV → CF2Cl + Cl.

2. Destruction of Ozone

I.e. O3(g) + Cl.(g) → ClO.(g) + O2(g)

3. Regeneration of Chlorine

I.e. ClO.(g)+ O.(g) → Cl.(g) + O2(g)

 

Written by Matrix Education

Matrix is Sydney's No.1 High School Tuition provider. Come read our blog regularly for study hacks, subject breakdowns, and all the other academic insights you need.

 

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