IB Overview 13.1Overview of IB topics

13.2IB Chemistry Practical Scheme of Work

1. 
   Preparation of a standard solution (0.40 hr). SL + HL – Students prepare a suitable standard solution (0.05 mol dm^-3 sodium carbonate.) They then calculate the exact concentration of this solution.
   

2. 
   Titration of a standard solution with an acid (1 hr 10 minutes). SL + HL – Using the prepared standard solution, students are asked to determine the concentration of a hydrochloric acid sample by titration.
   

3. 
   Water of Crystallization (1 hr 10 minutes). SL + HL – Students use heating to constant mass to determine the value of x in the following formula CuSO₄.xH₂O
   

1. 
   Flame Tests (0.40 hrs). SL + HL – Students carry out simple flame tests to show the identity of the following metal ions: Lithium, sodium, potassium, calcium, iron (II), copper (II), barium. This is used as an introduction to the concept of line spectra. The experiment is not assessed using IB criteria, though they are required to answer a series of questions regarding the excitation of electrons and write equations for these.
   

2. 
   Hydrogen Emission Spectrum (0.40 hr). SL + HL – Students explore interactive websites to investigate how emission spectra are related to the energy levels of atoms, convergence etc. Students are required to answer a series of questions relating to the emission spectrum. The following websites are used:
   

3. 
   First Ionisation Energies (1 hr). HL only – Students are given data regarding the ionisation energies across the third chemical period. They must suitably present this data and try to explain the trends. Students use this website as background reading for this experiment:
   

4. 
   Successive Ionisation Energies of Magnesium (0.4 hr). HL only – Students plot the ionisation energies and then attempt to explain them in terms of energy levels and electron orbitals. The experiment is not assessed using IB criteria, though they are required to answer a series of questions regarding the ionisation energies. This experiment is credited with ICT use of a databank.
   

1. 
   Reactions of the alkali metals with water (0.4 hr) SL + HL – Demonstration of the reactions of sodium, lithium and potassium with water. Students make observations and complete questions based on the observations.
   

2. 
   Halogen Displacement Reactions (0.4 hr) SL + HL – The halogens chlorine, bromine and iodine are placed in order of reactivity by observations of the colour changes involved during reactions with halide salt solutions.
   

3. 
   Chemical Tests for Ions (1 hr 50 minutes) SL + HL – Students complete tests for the following ions: Cations: copper (II), iron (II), iron (III), magnesium, aluminium. Anions: chloride, bromide, iodide, sulphate, carbonate, nitrate. Students are then required to identify five unknown slat solutions based on the tests completed.
   

4. 
   Transition Metal Complex ions (1 hr 10 minutes) HL only – Students complete several reactions investigating the transition complex ions. Metals investigated include manganese, copper, iron, cobalt and vanadium.
   

1. 
   Melting Points of Period 3 Elements (0.4 hr). SL + HL – The melting points of the elements in the third period are plotted on a graph and students complete a series of exercises explaining the trends. The melting points are obtained from this website:
   

2. 
   Transition Metal Complex Ions (0.4 hr). SL + HL – Reactions (reversible and non-reversible) reactions of the following transition metal complex ions are investigated: cobalt, copper, iron (II), iron (III), silver(I). Students are required to write balanced equations with states and draw and name the shape of some of the ions.
   

3. 
   Shapes of Molecules and Ions (1 hr 20 minutes) SL only – Students are shown videos on the school network and complete the questions at the internet website listed below to look at the shapes of various 2, 3, 4 negative charge centres.
   

4. 
   Shapes of Molecules and Ions (1 hr 20 minutes) HL only – Students are shown videos on the school network and complete the questions at the internet website listed below to look at the shapes of various 2, 3, 4, 5, 6 negative charge centres.
   

5. 
   Intermolecular Forces & Viscosity (1 hr) – Students complete the reading, questions and viscosity simulation at the following website:
   

http://wps.prenhall.com/esm_brown_chemistry_9/0,4647,171345-,00.html

1. 
   Exothermic and Endothermic Reactions (1 hr 20 minutes). SL + HL – Students are shown or carry out several reactions showing a range of exothermic and endothermic reactions. Examples of endothermic reactions include barium nitrate and ammonium chloride solids mixed together, dissolving ammonium chloride in water and thermal decomposition of copper carbonate. Examples of exothermic reactions include neutralisation, displacements reactions and the reaction of calcium and water.
   

2. 
   Enthalpies of Reaction (2 hr).SL + HL – Students are given the following instructions: “Investigate the enthalpy change for a common chemical reaction using a calorimeter”. The goal is to determine the enthalpy change per mole of reactant. (D, DCP, CE)
   

3. 
   Combustion of Alcohols Fuels (2 hrs). SL + HL – Students plan an experiment to determine which alcohol releases the most amount of energy per mole using methanol, ethanol, propanol and butanol. Students are issued with following instructions: “Determine which of the following fuels is the most efficient: methanol, ethanol, propanol and butanol?” The plan is that students use these fuels in spirit burners to heat a set volume of water and determine the enthalpy change per mole. They can then compare their results with literature values and give an evaluation of the success of the experiment. (MS, DC, DPP, CE).
   

1. 
   Factors Affecting Reaction Rates (1 hr) – Students use thiosulphate and acid reactions to measure how colour change can be used to monitor the progress of a reaction. They change the concentration of the thiosulphate to compare the rates. Data is recorded and matched to a graph to determine that this is a first order reaction.
   

2. 
   Decomposition of Hydrogen Peroxide (1 hrs) – Students use manganese dioxide to measure the rate of decomposition of hydrogen peroxide. The concentration of peroxide is changed and the results are graphed.
   

1. 
   Introduction to equilibrium systems (1 hr) – Students complete reactions to investigate the following equilibrium systems: precipitation of magnesium hydroxide, the tetrachlorocobalt complex ion, the effect of pH on the colour of bromine water, the effect of pH on chromate and dichromate. They are then required to write chemical equations and answers simple questions regarding Le Chatlier’s Principle and how it relates to these systems.
   

2. 
   Straw equilibrium (1 hr) – Students use measuring cylinders and straws to investigate the idea of equilibrium.
   

3. 
   Equilibrium simulation (1 hr) – Students are shown videos on the network and complete the activity on the website below:
   

4. 
   Investigating equilibrium using a pH probe (2 hrs) – Students use a Pasco pH probe to investigate the equilibrium system ethanoic acid/ethanoate ion/hydrogen ion and the ammonia/ammonium ion/hydroxide ion and the results when these stems are perturbed. They are then required to answer a series of questions explaining the principles learned.
   

1. 
   Properties of acids and bases. (1 hr) – A revision of the basic properties of acids including their reactions with metals, solid and aqueous carbonates, alkalis (including ammonia), bases and universal indicator. pH probes are also used. Strong monoprotic and diprotic acids and a weaker acid of the same concentration were investigated for their conductivity in a circuit measured in amps, and their pH using a pH meter. Their action with calcium carbonate and universal indicator was also observed. The same results were recorded for a strong alkali and weaker alkalis such as ammonia and solutions of sodium carbonate and sodium hydrogen carbonate. This experiment is credited with ICT use of a datalogger.
   

2. 
   Computer generation of titration curves (1 hr) - Students use the website listed below to complete a simulated titration of sodium hydroxide and ethanoic acid to determine the pKa of the acid.
   

3. 
   Determining the concentration of ethanoic acid in vinegar (2 hrs) - A sample of commercial vinegar is diluted and then titrated with a standard solution of alkali. The concentration of ethanoic acid is then found and compared with the value stated on the bottle.
   

4. 
   Investigating Buffers (1 hr) - Students use the website listed below to investigate buffers.
   

5. 
   Salt hydrolysis (1 hr) – Students test the pH using a pH meter of a range of salt solutions and answer questions based on conjugate acid/base pairs.
   

1. 
   Common examples of redox reactions (1 hrs) – Students complete a series of common redox reactions.
   

2. 
   Determination of the percentage of copper in brass (2 hrs) – Students prepare a standard solution of thiosulfate then react a brass screw with concentrated nitric acid and then after dilution, titrate with the standard solution.
   

3. 
   Investigating aqueous electrolysis (1 hr) - A range of aqueous salt solutions can be electrolysed. Students predict the products and compare these to their observations. They can then give electrode equations and discuss the factors that affect the products formed. Students also use both carbon and copper electrodes when electrolysis copper sulphate. The chlorine gas test is demonstrated.
   

4. 
   Investigating voltaic cells (2 hrs) – Students are instructed to investigate a factor which affects a voltaic cell. The idea is that students will chose cell voltage as the dependent variable and then chose one of the following independent variables: Size of electrodes, distance between electrodes, nature of electrodes, nature of solution, concentration of solution, nature of ion transfer (salt bridge), method of measurement. (D, DC, DPP).
   

5. 
   Investigating electrolysis (2 hrs) - Students are instructed to investigate a factor which affects electrolysis of a metal sulphate solution. The idea is that students will chose mass increase of the cathode (using a copper sulphate solution) as the dependent variable. They will then one of the following variables as the independent variable: time, temperature, concentration of solution, identity of metal/oxidation state, size of electrode, current, voltage. (D, DC, DPP).
   

1. 
   Dehydration of cyclohexanol (2 hrs) – Cyclohexanol is heated with phosphoric acid. The percentage of the product is calculated. The product is also tested for unsaturation using bromine water.
   

2. 
   Molecular Models (3 hrs) - Molecular models used for a number of applications throughout this topic. Various hydrocarbons are made to help illustrate structural isomerism. Reactions of alkenes shown. Students are able to build up different functional groups. Oxidation of alcohols and particularly condensation polymerisation reactions. Also optical isomerism.
   

3. 
   Esters (1 hr) – Several esters are formed by reacting alkanols and carboxylic acids.
   

4. 
   Preparation of an aldehyde (1 hr) - A sample of ethanol is oxidised with an acidified solution of sodium dichromate. The process is completed using a quickfit distillation kit. The aldehyde is collected for testing. The students are asked to perform this complex practical in pairs so that their teamwork, motivation and environmental awareness could be assessed. (Manipulative skills).
   

5. 
   Preparation of Carboxylic Acid (1 hr) - Ethanol is oxidised to ethanoic acid using acidified sodium dichromate in a quickfit reflux apparatus.
   

6. 
   Comparing the Rates of Hydrolysis of Halogenalkanes (2 hrs) - Chloro, bromo and iodopropane are hydrolysed with sodium hydroxide in a warm water bath. The rates of the hydrolysis reactions were monitored using silver nitrate to form a precipitate of the silver halide. The order of formation of these is explained in terms of bond strength.
   

1. 
   Structure Analysis (2 hours) – Students complete several exercises using Mass Spectroscopy, Infrared Spectroscopy and NMR to determine the structure of unknown organic compounds.
   

2. 
   Chromotography (1 hour) – Students complete chromatography of an unknown pigment and use Rf values to determine its identity.
   

3. 
   Atomic Absorption Spectroscopy (1 hour) - Students constructr a calicbration curve and use this to determine the concentration of an unknown.
   

1. 
   Research and Presentation (1 hr) – Students must research and prepare a poster to present on the development and history of a medicine. This should be done using internet research and using library resources.
   

2. 
   Synthesis of salicylic acid (1 hr) – Students prepare salicylic acid.
   

3. 
   Research and Presentation (3 hrs) – Students must research and prepare a poster to present on ‘Primary Pollutants’, They must then prepare a power point presentation on ‘Ozone’ and an information leaflet on either ‘Global Warming and Acid Rain’ or ‘Water pollution and Treatment’. This should be done using internet research and using library resources.
   

4. 
   Determining the Calcium and Magnesium content in Water (2 hrs) - Students are given a sample of water and must determine it’s calcium and magnesium ion content by titration with EDTA. They must then compare their results with the literature value on the bottle and evaluate their procedure.