Chemistry Flashcard Deck

Characteristics of Brass.

- Copper and Zinc.

- Hard, strong, shiny, looks pretty and doesn't corrode.

- Door locks, keys, knobs, ornaments and musical instruments.

Reaction at cathode when extracting aluminium.

4Al^3+ (l) + 12e^- -> 4Al(l) (Reduction)

Formula for Average Atomic Mass of a group of Isotopes.

(Ar of First Isotope x Abundance %) + (Ar of Second Isotope x Abundance %)...

Properties of Ionic compounds.

- High melting and boiling point.

- Usually soluble in water.

- Conduct electricity when melted or dissolved in water.

Properties of Covalent compounds.

- Low melting and boiling point.

- Usually insoluble in water.

- Doesn't conduct electricity.

Properties of Diamond.

- Giant covalent structure.

- Each carbon forms 4 carbon bonds.

- Very hard.

- Very high melting and boiling point.

- Doesn't conduct electricity as there are no delocalised electrons.

- Similar structure to Quartz (SiO2).

Properties of Graphite.

- Giant covalent structure.

- Each carbon forms 3 carbon bonds.

- Soft and Slippery as layers of strong carbon bonds side past each other.

- Good conductor of electricity as there are delocalised electrons due to 3 carbon bonds.

Properties of metals.

- Shiny.

- Malleable.

- Ductile.

- Good conductors of heat and electricity.

- Usually high melting and boiling point.

- Generally high density.

Purity Formula.

%Purity = Mass of pure substance / Total or impure mass

The Avogradro constant

6.02 x 10^23

Volume of gas at rtp

24 dm^3 / 24,000 cm^3

Gas mole formula at rtp

Mole = Volume/24 dm^3

Concentration of gas formula

Concentration = Mole/Volume

%yield formula

Actual yield/Theoretical yield x 100

Oxidation definitions

- Loss of electrons.

- Loss of hydrogen.

- Increase Oxidation number.

- Gaining Oxygen.

Waste products of hydrogen-oxygen fuel cells.

Water vapour, Heat and Unused air.

Advantage of hydrogen-oxygen fuel cells.

- Eco-friendly waste products.

- Hydrogen is easily available.

- Hydrogen is highly abundant.

Disadvantages of hydrogen-oxygen fuel cells.

- Hydrogen must be stored as a liquid under high pressure making it difficult and dangerous.

- Most hydrogen is from fossil fuels.

Activation energy (Ea) definition.

The minimum energy that colliding particle must have to react.

Enthalpy change definition.

Amount of heat energy given out or taken in during a chemical reaction.

Anhydrous Copper(II) Sulfate reaction.

CuSO4 (White) + 5H2O -> CuSO4.5H2O (Blue).

Anhydrous Cobalt Chloride reaction.

CoCl2 (Blue) + 6H2O -> CoCl2.6H2O (Pink).

Characteristics of Contact process.

2SO2 + O2 = 2SO3

- 450*C.

- 1-2 atm.

- Vanadium oxide (V2O5) Catalyst.

- 2SO2 -> Burning Sulphur.

- O2 -> Air.

Acid definitions.

- Proton donor.

- < 7 pH.

- High concentration of H^+ ions.

Bases definitions.

- Proton Acceptor.

- > 7 pH.

- High concentration of OH^- .

pH indicators.

Litmus paper -> Red, Blue.

Thymolphthalien -> Colourless, Blue.

Methyl orange -> Red, Yellow.

Types of acid reactions.

- Acid + Metal -> Salt + Hydrogen.

- Acid + Base -> Salt + Water.

- Acid + Carbonate -> Salt + Water + Carbon dioxide.

- Ammonium salt + Stronger base -> Water + Ammonium gas + Salt.

Amphoteric oxides

ZnO and Al2O3

Method to make salt using a metal, insoluble base or carbonate.

1) Add acid into beaker.

2) Add metal, insoluble base or carbonate until it no longer dissolves.

3) Filter solution.

4) Discard residue and collect filtrate.

5) Heat up filtrate on evaporation dish.

6) Cool down filtrate until crystals form.

7) Dry crystals in a warm oven.

Method to make salt using alkalis.

1) Place acid into conical flask and excess amount of base in burette.

2) Drop universal indicator in conical flask.

3) Slowly drop the base into the acid until pale green.

4) Repeat steps but with corrected amount of base and without universal indicator.

5) Heat up solution until the solution is saturated using an evaporation dish.

6) Cool solution down.

7) Dry crystals in warm oven.

Alkali metal characteristics

- Soft.

- Low melting and boiling point.

- Low density.

- Shiny.

- Reacts vigorously in water to form metal hydroxides.

- Reacts with oxygen to form metal oxides.

- Commonly forms ionic compounds with halogens.

Alkali metal trends.

- Melting and boiling point decreases.

- Reactivity increases.

- Density increases.

Observations of lithium reacting with water.

- Fizzes gently.

- Floats.

- Dissolves.

Observations of sodium reacting with water.

- Fizzes.

- Melts and forms a ball.

- Floats.

- Dissolves.

- Leaves a white trail.

- Yellow flame.

Observations of potassium reacting with water

- Melts and forms a ball.

- Fizzes vigorously.

- Dissolves.

- Floats

- Sparks.

- Burns with Lilac flame.

- Leaves a white trail.

Halogen trends

- Colour gets darker.

- Boiling and melting point increases.

- Reactivity decreases.

- Density increases.

Physical state and colour of halogens at rtp.

Fluorine -> Yellow Gas.

Chlorine-> Yellow/Green Gas.

Bromine -> Red-brown liquid.

Iodine -> Grey/black solid, forms purple vapour when heated.

Astatine -> Dark grey/black solid.

Properties of transition elements.

- High density.

- High melting and boiling point.

- Forms coloured compounds.

- Act as catalysts.

- Ions with variable oxidation number.

- Don't react to water.

Properties of non-metals.

- Poor conductors of heat and electricity.

- Brittle.

- Dull.

- Low melting and boiling point.

- Low density.

Saturated definition.

Solution with maximum concentration of solute at a certain temperature.

Alloy definition and examples.

- A mixture of two or more metals.

- Brass, Bronze, Stainless steel, Aluminium alloy.

Characteristics of Bronze.

- Copper and Tin.

- Hard, sonorous, resists corrosion.

- Coins, statues, bells, propellers for a ship.

Characteristics of Stainless steel.

- Iron, Chromium, Nickel, Carbon and other elements.

- Strong, resists corrosion and looks pretty.

- Cutlery and cooking utensils, construction and equipment in hospitals and factories.

Why is aluminium naturally resistant to corrosion?

Aluminium reacts rapidly with oxygen forming an aluminium oxide barrier which protects against further corrosion.

Reactions at anode when extracting aluminium.

- 6O^2- (l) -> 3O2(g) + 12e^- (Oxidation)

- C(s) + O2(g) -> CO2 (Reacts with carbon electrode)

Why is electrolysis not used to extract iron?

Electrolysis is very expensive due to high electricity demands and replacing electrodes.

Why can't aluminium be extracted using a blast furnace?

Aluminium is more reactive than carbon so it can't be displaced.

Weak acid definition.

An acid that partially dissociates into ions in an aqueous solution.

Strong acid definition.

An acid that completely dissociate into ions in an aqueous solution.

Element defintion

A substance made up of only one type of atom.

Compound definition

A substance formed when chemical elements are chemically bonded together.

Mixture definition

A combination of two or more substances that are not chemically combined.

Isotope definition

Atoms of the same element with different numbers of neutrons but same number of protons.

Ion definition

Atom/s with fewer or more electrons than protons resulting in a negative or positive charge.

Metallic bonding definition

Electrostatic attraction between positive metal ion and delocalised electrons

Empirical formula definition

The simplest ratio in which atoms combine to form a compound.

Molecular formula definition

The actual number of atoms of each element in a compound

General formula definition

Relationship between the number of atoms of each element within a molecule.

Functional group defintion

Atom/s which determine the chemical properties of a homologous series.

List general formula of Alkenes, Alkanes, Alcohol and Carboxylic Acid

CnH2n+2, CnH2n, CnH2n+1OH, CnH2n+1COOH

Fractional distilation step-by-step process

1) Petroleum is vaporised.

2) Column is hot at the bottom and cool at the top.

3) Lighter molecules move higher up column because they have lower boiling point.

4) Fractions condense when temperature in column falls below the boiling point of the fractions.

Characteristics of short molecules.

- Low melting and boiling point.

- Very volatile.

- Flows easily.

- Ignite easily

- Light in colour.

Characteristics of long molecules.

- High melting and boiling point.

- Not very volatile.

- Doesn't flow easily.

- Doesn't ignite easily

- Dark in colour.

List type of petroleum and what they're used for.

- Refinery gas -> Kitchen gas.

- Gasoline/petrol -> Fuel for cars.

- Naphta -> Cheap plastics.

- Kerosene/paraffin -> Fuel for planes.

- Diesel/gas oil -> Diesel engines.

- Fuel oil -> Ships and home heating systems.

- Lubricating oil -> Lubrication, waxes and polishes.

- Bitumen -> Road surfacing.

Describe the process of making ethanol through the hydration of ethene.

C2H4(g) + H2O(g) -> C2H5OH(g)

- Phosphoric Acid (H3PO4)

- 300*C, 60atm

List advantages and disadvantages of fermentation of glucose to make ethanol.

- Renewable.

- Low temperature and pressure.

- Slow.

- Done in Batches.

- Impure products.

- Yeast is killed when ethamol conc. is too high.

List advantages and disadvantages of hydration of ethene to make ethanol.

- Fast.

- Constantly running.

- Pure product.

- Non-renewable.

- High temperature and pressure.

List the processes of making ethanoic acid (vinegar).

- Ethanol + Acidified aqueous potassium maganate (Purple) -> Ethanoic acid (Colourless)

- Bacterial oxidisation of ethanol.

Reaction of Ester

Alchol + Carboxylic acid = Ester + Water

- Sweet smelling.

- Very volatile.

- Catalyst is HSO4

- COC=O

Polymers defintion

Long chain formed from many small molecules joined together.

Monomers definition

A small molecule that joins together together to form a polymer.

Addition polymers and their uses

- Polyethene -> Plastic bags

- Polypropene -> Water pipes

- Polychloroethene -> PVC

Reaction to make Nylon

Dicarboxylic acid + Diamine -> Nylon + 2nH2O

- Functional group: O=CNH

- Polyamide

- Condensation Polymer

- Synthetic Polymer

Reaction to make Protein

Amino acid + Amino acid -> Protein + 2nH2O

- Functional group: O=CNH

- Polyamide

- Condensation Polymer

- Natural Polymer

Reaction to make PET

Dicarboxylic acid + Diol -> PET + 2nH2O

- Functional group: O=CO

- Polyester

- Condensation Polymer

- Synthetic Polymer

Mole Formula

Moles = Mass/Molar mass

OH- reaction at anode.

4OH^- -> O2 + 2H2O + 4e^-

Reaction at anode in hydrogen-oxygen fuel cells.

2H2 -> 4H^+ + 4e^-

Reaction at cathode in hydrogen-oxygen fuel cells.

O2 + 4H^+ + 4e^- -> 2H2O

Characteristics of Dynamic Equilibrium.

- The forward and reverse reactions remains equal at the same rate.

- The concentrations of reactants and products remain constant.

- Can only occur in closed system.

Characteristics of Haber process.

N2(g) +3H2(g) = 2NH3(g)

- 450*C.

- 200 atm.

- Iron (Fe) Catalyst.

- Used for Fertilisers and Bombs.

- N2 -> Air from fractional distillation.

- 3H2 -> Methane.

2 ways to identify redox reaction.

- Acidified aqueous Potassium Manganate (KMnO4(aq)), Purple -> Colourless.

- Aqueous Potassium Iodine (KI(aq)), Colourless -> Yellow-brown.

Insoluble and soluble salt rubric

1) Na, K and NH4 are always soluble.

2) NO3 is soluble.

3) SO4 is always soluble except with Pb(II), Ba and Ca.

4) Cl is always soluble except with Pb(II) and Ag.

5) CO3 is always insoluble except when Step 1 is applied.

6) OH is always insoluble except when Step 1 is applied.

Word and Symbols equation for Iron rusting.

Iron (4Fe(s)) + Oxygen (3O2(g)) + Water (XH2O(l)) -> Hydrated iron oxide (2Fe2O3.XH2O(s))

Reactions in blast furnace.

Reactants: Hematite (Fe2O3), Limestone (CaCO3) and Coke (Almost pure carbon).

1) C(s) + O2(g) -> CO2(g), gives heat and reacts carbon with air. (Exothermic).

2) C(s) + CO2(g) -> 2CO(g), carbon dioxide is reduced. (Reduction).

3) Fe2O3(s) + 3CO(g) -> 2Fe(l) + 3CO2 (g), carbon monoxide reduces iron(III)oxide. (Reduction).

4) CaCO3 -> CaO(s) + CO2(g), limestone is thermal decomposed. (Thermal decomposition).

5) CaO(s) + SiO2(s) -> CaSiO3(s), Calcium oxide reacts with sand (SiO2) forming slag. (Acid-Base Reaction).

Overall reaction of Bauxite during electrolysis.

2Al2O3(l) -> 4Al(l) + 3O2(g)

Precipitation definition

A reaction in which two soluble substances react in solution to form an insoluble solid

Homologous series definition

Group of compounds with the same chemical properties because they have the same functional group.

Isomers definition

Compunds with the same molecular formula but different displayed/structural formula.

List optimum temperature and catalyst for cracking

600-700*C, Alumina (Al2O3), Silica (SiO2)

Formula of making ethanol through fermentation.

C6H12O6(aq) -> 2C2H5OH(aq) + 2CO2

Electrolysis definition

The decomposition of an aqeous ionic compound by an electric current being passed through.

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