Demonstration of ionic movement: Name the chemicals required, the colour of each and the colour of the mixture.
1. Take
blue Cu�?
and
yellow CrO?�?
ions and dissolve in
conc ammonia (colourless)
urless)*. The resulting mixture is green.
2. Place a drop of the solution on filter paper wrapped around a glass slide.
3. Connect filter paper to 20V power supply.
4. The
How is a solution of iodine made up? (word equation)
Excess iodide + iodate + sulfuric acid ? iodine + water
(IO?? + 5I? + 6H? ? 3I? + 3H?O)
When finding the concentration of hypochlorite in bleach, what is the bleach first reacted with?
1. The bleach is first diluted
2. Bleach + iodide + H?SO? ? iodine solution
3. The bleach is titrated against thiosulfate
(ClO? + 2I? + 2H? ? Cl? + I? + H?O)
Give the balanced chemical equation for the formation of ethyne. What three impurities are formed? What is the gas bubbled through?
CaC? + 2H?O ? C?H? + Ca(OH)?
Hydrogen sulfide (H?S), phosphine (PH?) and ammonia (NH?)
The gas is bubbled through copper sulfate.
Give and example of an endothermic and exothermic reaction
Endothermic:
Add citric acid to
sodium hydrogen carbonate (NaHCO?)
Exothermic:
Place a magnesium strip into HCl
Steam reforming of methane equations
CH? + H?O ? CO + 3H?
CO + H?O ? CO? + H?
Experiment on monitoring reaction rate equation
2HCl + Na?S?O? ? 2NaCl + S? + SO? + H?O
Reaction between HCl and marble chips
2HCl + CaCO? ? CaCl? + CO? + H?O
Equations involving combustion
X + O? ? CO? + H?O + balance
Explain, using equations how rain becomes acidic
N? + O? ?2NO
- high temperature of car spark plugs provides the energy required for this reaction
2NO + O? ? 2NO?
2NO? + H?O ? HNO? + HNO?
i.e
N? + O? + O? + H?O ? HNO? + HNO?
Remember by: nooho ? nitric acid + nitrous acid
What reactions are catalysed in a catalytic converter?
1. CO + �/?O? ? CO?
2. 2CO + 2NO ? 2CO? + N?
3. Octane + O? ? H?O + CO? + balance.
Balanced chemical equation for the demonstration on the intermediate formation theory. State the colour changes that take place.
C?H?O?�? + H?O? ? H?O + CO?
Co�? catalyst
st*
C?H?O?�? is potassium sodium tartrate.
This is an oxidation reaction.
At the start it is pink because of the Co�?
It then turns Green because of the intermediate.
It then turns pink again because the Co�? is r
Equation for the hot platinum experiment
2Methanol + O? ? 2Methanal + 2H?O
Pt catalyst
Remember, this is an oxidation reaction
Free radical substition
Initiation
Cl�Cl ? Cl� + Cl�
Propagation
H?C�H + Cl� ? CH?� + H�Cl
CH?� + Cl�Cl ? CH?Cl + Cl�
Mention chain reaction
Termination
CH?� + CH?� ? C?H?
Cl� + Cl� ? Cl?
Cl� + CH?� ? CH?Cl
Note:
CH? may be replaced by any alkyl group
Draw the structure of the products formed when ethene reacts with bromine water containing sodium chloride. (The three products are listed on the syllabus, but I'm not absolutely sure if you need to know them.)
Reagents needed for esterification
Heat, conc H?SO?
Esterification and base hydrolysis: in which type of reaction do the molecules lose a molecule of water, and in which type do the molecules gain a molecule of water?
Esterification: lose a molecule of water
Base hydrolysis: Gain water
Soap monster equation
Formation of ethene reaction
C?H?OH + heat ? C?H? + H?O
Al?SO? catalyst
Reduction reactions of organic compounds
Aldehyde + H? + Ni,heat ? Alcohol
Reaction of ethanoic acid with magnesium metal
2C?H?COOH + Mg ? Mg(C?H?COO)? + H?
Reaction of ethanoic acid with sodium hydroxide
C?H?COOH + NaOH ? C?H?COONa + H?O
Reaction of ethanoic acid with sodium carbonate
2C?H?COOH + Na?CO? ? 2C?H?COONa + H?O + CO?
Organic synthesis: synthesis of PVC
1. Ethene is chlorinated to form 1,2 dichloroethene
2. Heated to vaporisiation to form HCl and 1,chloroethene
3. Polymerised by heating in the presence of a catalyst.
(pic from wikipedia)
Haber process: equation, catalyst, conditions
N? + 3H? ? 2NH?
iron catalyst
673K, 200atm
Equation for the equilibrium between iron(III) and thiocyanate
Fe�? + CNS? ? Fe(CNS)�?
Fe�?: yellow
Fe(CNS)�?: red
Equation for the equilibrium between Cobalt chloride and water
CoCl?�?
+ 6H?O ?
Co(H?O)?�?
(H?O)?�?* + 4Cl?
blue ? pink
Equation for the equilibrium between chromate(VI) ions and water.
Cr?O?�?
+ H?O ?
2CrO?�?
orange ? yellow
Contact process: equation, catalyst, conditions
SO? + �/?O? ? SO?
713K
1 atmosphere
V?O? - vandium pentoxide catalyst
Self ionisation of water
H?O + H?O ? H?O? + OH?
What happens to stearic acid in hard water? Why does it waste soap?
Ca�? + 2C??H??COO? ? (C??H??COO)?Ca? (scum)
Soap is used up in this reaction to make scum and therefore wasted.
What happens when water containing temp hardness is boiled? Give equations
Ca(HCO?)? + heat ? CaCO? + CO? + H?O
How does temporary hardness occur? Give equations.
CO?(g) + H?O(l) ? CO?(aq)
CO?(aq) + H?O ? H?CO?
H?CO? + CaCO? ? Ca(HCO?)? (soluble ? it dissolves in water)
How are heavy metal ions removed from water? Give the equation.
Precipitation
Pb�? + 2OH? ? Pb(OH)??(insoluble)
Ionic equation for edta (actually on the syllabus)
H?Y�? + M�? ? MY�? + 2H?
M�? stands for either Ca�? or Mg�?
H?Y�- is edta
Winkler method: equations (probably don't need them, just remember the reagents)
1. Under alkaline conditions, MnSO? produces a white precipitate of Mn(OH)??
Mn�? + 2OH? ? Mn(OH)??
2. If present, oxygen oxidises this to form a brown precipitate. If there is no oxygen, then the white precipitate remains.
Mn(OH)? + O? ? MnO(OH)??
3. Thi
Magnesium oxide manufacture:
What is made out of CaCO3? Give equations and the processes required
CaCO? + heat in kiln -> CaO + CO?
CaO + freshwater -> Ca(OH)2 slaking
Magnesium oxide manufacture:
What is made out of seawater? Give equations and the processes involved.
1. Remove sand and particles (settle in reservoir)
2. Remove CO?
3. Acidify with H?SO?
MgCl?
Magnesium oxide manufacture:
How is the feedstock converted to the product?
Ca(OH)? + MgCl? ? Mg(OH)? + CaCl? (simple swtch)
Mg(OH)? +heat ? MgO + H?O
MgO + pellet mill ? MgO pellets.
How is nitrogen fixed by lightning? Give the chemical equations
N? + O? ? 2NO
lightning provides energy for this reaction
2NO + O? ?2NO?
2NO? + H?O ? HNO? + HNO?
i.e N? + O? + O? + H?O ? HNO? + HNO?
Remember by: nooho ? nitric acid + nitrous acid
Same as car exhausts producing acid rain except lightning provides the e
How do oxides of sulfur get into the air? How do they cause acid rain? Give equations
SO? is formed by burning fossil fuels, volcanoes, and decay of organic matter.
SO? causes sulfurous and sulfuric acid to become dissolved in water.
Sulfurous acid:
SO? + H?O (dissolving in water)? H?SO?
Sulfuric acid:
SO? is oxidised to SO? in the atmosph
Give the chemical equations for scrubbing
CaCO? + heat ? CaO + CO?
CaO + SO? ? CaSO?
Fermentation equation
Glucose ? 2 carbon dioxide + 2 ethanol
C?H??O? ? 2CO? + 2C?H?OH
How is Carbon monoxide formed?
When carbon is burned in a limited amount of oxygen:
C + �/?O? ? CO
How is ozone formed in the atmosphere?
O? + energy (uv light) ? O� + O�
O? + O� ? O?
Write an equation for the photo-dissociation of ozone
O? + uv ?O? + O�
(By absorbing the uv light in this way, ozone stops it from reaching the surface of the earth)
Other than photo-dissociation, how is ozone broken down?
1. Reaction with NO
2. O� + O? ? 2O?
Explain how CFCs destroy ozone molecules (long explanation)
1. CFCs broken down by uv to form Cl� in the atmosphere
2. The Cl� radicals attack O?: Cl� + O? ? ClO� + O?
3. There is a chain reaction: ClO� + O� ? Cl� + O?
4. These Cl� radicals will continue to attack more ozone molecules
www.youtube.com/watch?v=I1wrE
Give chemical equations for what methane does to the ozone layer
Methane removes individual chlorine atoms from the stratosphere as follows.
CH? + Cl� ? CH?� + HCl
As HCl does not destroy ozone, this reaction is protective of the ozone layer.
Antarctic conditions can change HCl into chlorine molecules. These may be bro
What three chemical species form as a result of carbon dioxide gas dissolving in water? (2008, 2007)
HCO?? (Hydrogencarbonate)
CO?�? (Carbonate)
H?CO? (Carbonic acid)
How would you make SO? for the demonstration of the effect of SO? on universal indicator solution. And while we're at it, what is the effect?
HCl + Na?SO? ? SO? + other stuff
Effect is that the solution goes red
Electrolysis of aqueous sodium sulfate: Reactions at positive and negative electrode 2005 11a
Positive: H?O ? 2e? ? �/?O? + 2H?
Negative: 2H?O + 2e? ? H? + 2OH?
Electrolysis of KI with inert electrodes: half reactions of reactions at positive electrode and negative electrode. 2009 10b
Positive: 2I? ? 2e?? I?
Negative: 2H?O + 2e?? H? + 2OH?
Give half reactions for the reactions that occur at the positive and negative electrode when an electric current is run through acidified water.
Positive: H?O ?2e? ? 2H? + �/?O?
Cathode: 2H? + 2e? ? H?
Equation for silver electroplating
Positive: Ag ? e? ? Ag? the anode dissolves
Negative: Ag? + e? ? Ag spoon gets coated with silver
Electrolysis of copper sulfate using copper electrodes: give the equations for the reactions that occur at the anode and cathode.
Positive: Cu ? 2e? ? Cu�? the anode dissolves
Negative: Cu�? + 2e? ? Cu? cathode increases in size
Full reaction: Reaction of halogens with Sulfite
Cl? + SO?�? + H?O ? 2Cl? + SO?�? + 2H?
Half reaction of oxidising agents: Reaction of halogens with Sulfite
Half reaction of reducing agents: Reaction of halogens with Sulfite
Oxidising: SO?�? + H?O ? SO?�? + 2H? + 2e?
Reducing: Cl? + 2e? ?2Cl?
Give the equation for the displacement of copper from a solution of its salts using scrap iron.
Fe + Cu�? ? Fe�? + Cu?
Also write down Fe + CuSO? ? FeSO? + Cu?
Give the equations for the two displacement reactions on the syllabus. What is the result in each case?
Mg + Cu�? ? Mg�? + Cu?
Zn + Cu�? ? Zn�? + Cu?
Result:
1. The magnesium/zinc gets coated with copper.
2. Blue colour of copper sulfate fades
Write full reactions as well, replace �? with SO?
Half equations of reducing agents:
1. Reaction of halogens with Bromides
2. Reaction of halogens with Iodides
The bromides and iodides are the reducing agents as they get oxidised. They can only get oxidised by an element which is higher than them on the periodic table (Br? can get oxidised by Cl? and and F?, I? can get oxidised by F?, Cl? and Br?).
The reducing
Half equations of oxidising agents (Cl? and Br?): Reaction of halogens with Bromides and Iodides
Cl? can oxidise bromides and iodides
Br? can only oxidise iodides, as it is a weaker oxidising agent.
The oxidising agents are reduced as follows.
Cl? + 2e? ? 2Cl?
Br? + 2e? ? 2Br?
Write an equation for the emission of gamma radiation by Cobalt 60
????Co ? ????Co + energy
(pg 35)
Equation for first and second ionisation energy
First: X ? X? + e?
Second: X? ? X�? + e?
(note to self: second ionisation energy is the energy required to remove the second electron only, not the energy to remove both electrons)
Chloride anion test
Add silver nitrate:
Ag? + Cl? ? AgCl?
PR: White precipitate soluble in dilute ammonia
Sulfate/Sulfite anion test
Add BaCl?:
Ba�? + SO?�? ? BaSO?? Sulfate
Ba�? + SO?�? ? BaSO?? Sulfite
PR: White precipitate formed
Sulfate/Sulfite distinguishing test
ppt dissolves in dilute HCl ? Sulfite
ppt remains in dilute HCl ? Sulfate
SO?�? + 2H? ? SO? + H?O
BaSO? + HCl ? no reaction
Nitrate anion test
Add FeSO?
Add conc H?SO?
PR: Brown Ring
Phosphate anion test
Add ammonium molybdate
Add conc nitric acid
Warm
PR: Yellow precipitate
Carbonate/Hydrogencarbonate anion test
Add HCl, bubble through limewater
PR: Fizzing, turns limewater milky
CO?�? + 2H? ? CO? + H?O
HCO?? + H? ? CO? + H?O
Carbonate/Hydrogencarbonate distinguishing test
Add Magnesium Sulfate
Mg�? + CO?�? ? MgCO?? (insoluble, white ppt)
Mg�? + 2HCO?? ? Mg(HCO?)?? (soluble, no ppt)
Why does limewater turn milky when CO? is passed through it? Why does it eventually disappear?
Ca(OH)? + CO? ? H?O + CaCO??(Chalk - white colour)
It disappears because eventually, CaCO? + CO? + H?O ? Ca(HCO?)??(soluble)
When a white precipitate is not formed after the Carbonate/Hydrogencarbonate distinguishing test, why does boiling result in a precipitate? Give the equation.
Mg(HCO?)? ? CO? + H?O + MgCO??(insoluble)
Illustrating bond energies by
showing how the C-H bond
energy in methane is
calculated.
CH? ? C + H?
Heat of reaction = 1648
There are four bonds broken, so the bond energy is
�/?(1646) = 412
Decomposition of hydrogen peroxide
H?O? ? H?O + �/?O?
MnO? catalyst, or KI catalyst
Example of autocatalysis with equation (kinda unsure if you need to remember the equation or not. Up to you guys if you want to remember it or not)
MnO?? + 5Fe�? + 8H? ? Mn�? + 5Fe�? + 4H?O
Mn�? acts as a catalyst
Example of homogeneous catalysis with equation
H?O? ? H?O + �/?O?
KI catalyst
Example of heterogeneous catalysis with equation
Haber process:
N? + 3H? ? 2NH?
Iron catalyst
Describe the mechanism of the ionic addition of chlorine/bromine to ethene (2013 8c, 2012 10a, 2010 9c, 2008 9d,
1. Polarisation of Cl? by electron rich double bond (Cl?? � Cl?? at right angles). [Line essential]
2. Heterolytic fission of chlorine molecule. Cl? ? Cl? + Cl?) (don't draw the Cl molecules bonded together, don't put a ?)
3. Addition of Cl? (not Cl??) to
Equation of polymerisation
Half reactions of Oxidation of aldehydes by
(i) Potassium permanganate
(ii) Fehlings reagent
(iii) Ammoniacal silver nitrate
(i) Mn?? + 5e?? Mn�?
purple ? colourless
(ii) Cu�? + e? ? Cu?
blue ? brick red
(iii) Ag? + e? ? Ag?
colourless ? silver mirror
How are phosphates and nitrates removed from sewage water?
Phosphates are removed by adding Al?(SO?)? to form an insoluble salt
Nitrates are removed using biological denitrification. The nitrates are placed in a tank with no oxygen. Then microorganisms take oxygen from the only source available, reducing the nitr
Colorimeter experiment: A sample of swimming pool water is colourless. How could a colour be introduced into the sample so that the colorimeter may analyse it?
Acidified KI (potassium iodide) is added. (ethanoic acid is used to acidify it)
A reaction similar to the following occurs. Cl may be replaced with other free chlorine species.
Cl? + 2KI ? I? + 2KCl
The more concentrated the free chlorine is in the water,
Draw the structure of eugenol
When may ethanol reacts as an acid? Give the equation
They will only react with very reactive metals such as sodium.
C?H?OH + Na ? C?H?ONa + �/?H?
C?H?ONa is sodium ethoxide.
Bromine and potassium iodide (aq.) reaction
Br? + 2KI ? 2BrK + I?
Phenylmethanol equation. What is the name of the intermediate formed?
3(Phenylmethanol) + 3KMnO? ? 3(Benzoic acid) + 4MnO? + H?O + 4KOH
Sodium benzoate is formed as an intermediate. HCl is used to convert it to benzoic acid
Reaction of halogens with Fe. How do you confirm the presence of iron (III)?
Add chlorine water to FeSO?
Equation: Cl? + 2Fe�? ? 2Cl? + 2Fe�?
Test: Add NaOH ? green precipitate of Fe?O? (Fe�? ions)