This is a 3-part commentary on the new syllabus, which begins examination in May 2016, and is thus relevant to the first years coming in Sept 2014. These are meant for IB chemistry teachers, and especially for those who have taught the 2009 syllabus. The first part speaks about the philosophical differences, the second (this part) is a topic-by-topic comparison, and the last part talks about the changes in Internal Assessments. All opinions are entirely mine, and I am not affiliated with IBO. As a personal project with no editorial help, there is bound to be errors and omissions; your comments would be most welcomed.
The overall structure of the syllabus is preserved but with varied proportions.
- The lab component stays the same, with Group 4 project intact. However, there is now a list of prescribed experiments (examined in paper 3). The internal assessment undergoes a historical change-over, from a portfolio of experiments to a 10-hour IA — in-line with other groups — using new criteria. This will be examined in more detail in the next post.
- The options are reduced from “7-choose-2” to “4-choose-1”, with overall hours reduced from 45 to 25.1
- Core and HL material now incorporate material from the removed options. Most obvious is the inclusion of spectroscopic techniques, but environmental and organic also saw themselves into the core/HL material as well.
I am very happy about the addition of spectroscopy as a mandatory topic. Spectroscopy is bedrock to modern chemistry, but it is neither something that students are able or willing to learn on their own. In the past I have made analytical chemistry a compulsory option, but students would privately opt out: now we assert that this is important and they all need to know it.
While the 2009-2015 syllabus2 topics comprised solely of assessment statements3, the 2016 syllabus is much richer in content but omits the assessment statements. This omission was intentional, as examiners feel that the presence of assessment statements restricts the question they can pose in exams.4 The content of each topic is instead split into sections such as “understanding”, “skills”, “applications”, “theory of knowledge”, and “cross-curriculum links”. I love this decision. The assessment statements encourages a piece-meal, insulated “study for exam” mindset, whereas the current approach is both richer and more holistic.5
What is missing from the guide, however, are the hours recommendations. The 2009-guide recommend teaching hours by the sub-topic, for example, 1 hour for the reactions of organic alcohols. The 2016-guide, on the other hand, simply gives the teaching hour by a topic: there would simply be a recommendation of 11 hours for “organic chemistry”.
For teachers new to the IB, the new syllabus, broad and holistic as it is, would be much harder to start teaching with. However, since there is substantial parallel between the 2009 and 2016 guides, I would recommend planning lessons with both guides on the first go-around, since the assessment statements provide concrete tasks that your students need to be able to do; they would also be able to look at the old sub-topic hour recommendations and extrapolate to the new syllabus. You can consult the map in the next section to find the mapping.
While there are limited changes to the material included — chemistry is a mature discipline — the topics are often numbered differently. There is a general push in combining multiple sub-topics into a new one; for example, what used to be “3.2 physical properties in periodic table” and “3.3 chemical properties in the periodic table” is now simply “3.2 periodic trends”. Sometimes this gives better clarity to the syllabus, but sometimes I feel it overshot (for example, both core kinetics and equilibrium have exactly one sub-topic, which is no help at all when it comes to teachers structuring their year plan).
Sitting down with both guides side-by-side, I charted the mapping of each topic, and annotated the addition and removal of material. I then cross-referenced this against the list by David Allen. This post will get elaborated on as I gain a fuller understanding of the new syllabus. You can download a printable copy (designed to print on an A3 page) as a PDF here.
Each topic sits in its own box, with a horizontal line demarcating where the HL material begins. On the left are the topic numbers / titles from the 2009 guide (over a blue background ); on the left are the topic numbers / titles from the 2016 guide (over a green background). The numbers next to the the units, with a pink background, are the hours. These hours are extracted for the old guide, and extrapolated by me to the new sub-topics after mapping each units. (That is, the hours for the new sub-topics are not official.)
Blue arrows show mapping of a 2009 sub-topic to a 2016 sub-topic, at the same level (e.g., HL->HL). Red arrows indicate where a previously HL topic is relocated to a SL topic, whereas green arrows denote a SL -> HL transfer. Dashed lines show partial mapping.
Important notes on the new sub-topics are given in red font under each title:
Let’s look at the changes in each topic one at a time, in bullet-points, followed by my comments in square brackets.
1: Stoichiometric relationship
- The topic is renamed from quantitative chemistry to stoichiometric relationships. [I think this is just cosmetic.]
- A sub-topic of the 1.1 particulate nature of matter is added. [This makes explicit something that we all taught, or expect students to know as prior background. I like this, especially the mentioning of mixed states of matter.]
- Within the concepts in 1.1 some are newly explicit, including the distinction between homogenous and heterogenous phases.
- Within 1.1 is a mentioning of atom economy. [While links in stoichiometry right away to environmental concerns, I suspect that this will have to be tackled after finished with the rest of stoichiometry. It certainly would take a fair bit of time to grasp.]
- Mole concept is mapped directly, with a special emphasis of ozone pointed out as an application.
- the rest of stoichiometry is simply smushed into one sub-topic.
- An associated change with the gas laws is hidden in the revised data booklet: what used to be incorrectly called STP is correctly referred to as SATP (Standard Ambient Temperature and Pressure). This is a much welcomed correction, and would prevent student confusions about the different “standard” encountered in gas laws and thermodynamics.
2: Atomic structure
- Concepts regarding the nucleus is condensed into a single section 2.1. This includes mass spectra.
- While mass spectra is included, the instrumentation is not; no more vaporization-ionization-etc. I like this cut: sector mass spectrometers declined in importance since the 90’s, and is now eclipsed by time-of-flight / quadrupole instruments. (If I were designing the curriculum, I’d probably introduce ESI-ToF as a principle for how mass spec work: it’s intuitive and relevant.)
- Electron arrangement (i.e., “2.8.2”) is entirely out, replaced by uniformly using only electron configuration (i.e., [He]2s1) in both SL and HL. This change is needed to buttress some other changes in the syllabus (in bonding, then with aromatic compounds), and would remove the confusion of notation for HL students6.
- Trends in ionization energy and conversion between energy and frequency of light7 is relocated as a HL-only section 12.1.
- Physical and chemical properties, previous separated into different sections, is condensed into one 3.2 periodic trends.
- Within 3.2 are properties of row 3 oxides, previously a portion of HL topic (13.1)
- The other half of ex-13.1, the row 3 chlorides, are removed entirely.
- Note that Allen’s post, he comments that “similarities and differences between elements in the same group” is out; this contradicts the guide in that a key understanding is “vertical and horizontal trends in the periodic table”.
- The first-row d-block elements have been officially expanded into two topics, 13.1 & 13.2. In 13.2 is the formal treatment of colored complex and their origins; this is implicit in the 2009 syllabus, and covered in Brown & Ford.
- Transition elements is now redefined to include scandium (Sc).
4: Structure and bonding
- For structure and bonding, the major change is distributing physical properties (ex-4.5) into each bonding topic.
- There is no removal of content, only addition.
- Covalent bonding used to be a behemoth topic, and is now broken into the nature of bonding (4.2) and structures (4.3).
- 4.3, covalent structures, now include resonance structures, previously an HL topic. This was previously prepared by including electron configuration as part of topic 3, and path the way for aromatic structures in organic.
- The family of carbon allotropes is expanded to include graphene. This keeps up with the times, even though I would have add carbon nanotube and expand on this as a discourse of topology…
- HL section 14.1 is a grab-bag of concepts, several aspects being put together from previous 14.1/2. The most note-worthy addition is the assignment of formal charges.8
- I am unhappy about the inclusion of the obviously wrong statement “strength of dispersion forces < dipole-dipole forces < hydrogen bonds” in the syllabus.9
- Some clarification of terminology:
- instantaneous induced dipole-induced dipole is explicitly referred to as London forces (synonymous with dispersion forces), and
- Van de Waal’s forces is redefined as all of London (induced dipole–induced dipole), Debye (permanent dipole–induced dipole), and Keesom forces (permanent dipole – permanent dipole).
- Coordinate bonds exclusively used in place of dative bond
- Electron domains now used in place of negative charge centers.
- If you have been looking at the graphics, you would have noticed the addition of ozone as an application here. Someone really like ozone… in this section, the role of CFC is especially highlighted.
- There is rearrangements but no major changes in the SL syllabus.
- As with many other topics, there are now explicit applications specified… and as with many other topics, it’s ozone that is specified. I am personally ambivalent about so much emphasis on ozone. On one hand it’s a a nice story linking chemistry and society — where for once humanity did the right thing — on the other hand the chemistry of ozone in the stratosphere is far more complex than can be understood at the IB level.
- Drugs is explicitly specified as an application as well. I am very tempted to include a ligand-receptor simulation as an investigation.10
- HL topic 15.1 is a combination of what used to be 15.1 and 15.2.
- In addition, however, 15.1 also adds solvation to the variety of standard enthalpies. I think this is a wonderful addition and supports a more accurate view of what “dissolve” means.
- Even though 15.2 is a mere consolidation of entropy and spontaneity, with no addition of material, it would probably need to be taught differently. In the 2009-syllabus, Gibbs free energy is treated as an afterthought, a dead end that leads nowhere. In the 2016-syllabus ΔG is back in its rightful place, central to physical chemistry: there is now link to equilibrium (ΔG = -RT lnK) and electrode potentials (ΔG = -nFE), so students would need a better grasp of the concept than before.
6: Chemical kinetics
- My reading of the syllabus is that there is nothing added or taken away, in both HL and SL syllabus. This confuses me because there is 2 extra hours allocated to the SL syllabus. (Allen mentioned that potential energy profiles are added, but I think that it has always been in.)
- I wish the integrated rate laws would be back in, but I think it’s wishful thinking considering the general deterioration of mathematical / arithmetic prowess.11 Without integrated rate laws, there is absolutely no reason to acquire a time-series in practical investigations — but the IB ask questions about time-series anyway.
- Woohoo! Reaction quotient Q is in! The existing way of dealing with changes in equilibrium was making predictions with La Chatelier’s principle, which is fine in a general hand-waving way but falls apart in numerous occasions.12
- Liquid-vapor equilibrium is explicitly removed. Since it is just an extension of intermolecular forces / enthalpy of vaporization, however, I am not sure if it is entirely removed.
- In 17.1, the equilibrium law (previously 17.2) now includes the relationship between ΔG with equilibrium constant K. I love this change — it nudges students to a coherent, holistic view of thermodynamics, kinetics, and equilibrium.
8: Acids and bases
- Lewis acids and bases are moved from SL to an HL section (18.1).
- Salt hydrolysis (ex-18.3) is removed from the syllabus entirely.
- Allen mentioned that buffers are removed; my reading of the guide is that it’s moved to topic 18.3.
- Titrations, indicators, and graphical representations are consolidated into 18.3
- The term pH curves will replace titration curves.
- pOH is removed from SL (?), and temperature dependence of Kw is now an HL-only topic (in 18.2)
- New is 8.5, acid deposition. This used to be in Opt E, Environmental chemistry; the entire option is broken down and rolled into the core syllabus.
- Amphiprotic and amphoteric species are explicitly defined in this unit (previously spread over ex-13.1 and 8).
9: Redox processes
- No content is removed from either SL or HL syllabus.
- The general clumping of topic happens again here; 9.1 contains all the foundation of redox (previously 9.1-9.3), and 9.2 contains both voltaic / electrolytic cells.
- New to redox is the explicit inclusion of Winkler titration for the determination of dissolved oxygen. This is another environmental connection. (This is a specific example of a redox titration; presumably permanganate titration, having showed up in May 2013 paper 2, will also be included amongst other redox titrations.)
- Fuel cells is included as one of the applications for redox chemistry. I think this used to be in the Technology / Chemical Industry option.
- New to the HL syllabus is the connection between Gibbs free energy and standard electrode potential. Since ΔG is previously connected up to K, students would now be able to see the connection between redox and equilibrium as well (and thus be able to make sense of the equilibrium signs in the standard electrode potential data tables).
- For HL there is an explicit mentioning of electrochemical cells in series. I don’t feel strongly about its inclusion, one way or another. Often questions on this just become another disconnected intellectual exercise
10: Organic chemistry
- There is major rearrangement in this unit. Topic 10/20 in the 2016-syllabus is an amalgam of what used to be 10/20/Opt G. Together with the change in topic structuring, I am not very certain that I have picked out all the changes.
- Nomenclature of nitrogen containing functional groups are out; that is, no nomenclature of amines, amides, or nitriles. Nomenclature of alkynes are in, and nomenclature of esters are now in the core syllabus (previously HL-only).
- Benzene is included in the core functional group chemistry; electrophilic substitution is in the HL syllabus (previously Opt G).
- Reduction of carbonyls (e.g., with LiAlH4, NaBH4) are now in. This is a nice complement to the staple oxidation of alcohols.
- Markonikov (presumably also anti-Markonikov?) addition is now in.
- SN1/SN2 is moved from SL to HL.
- Elimination and condensation, according to Allen, is no longer in either SL/HL syllabus.
- In stereoisomerism (prev 20.6, now 20.3), the E/Z nomenclature is introduced. (But not R/S for optical isomers.) The E/Z notation, together with the cis/trans notation, would displace the term “geometric isomerism”.
- An understated change is the number of steps present in a synthetic route: it used to be 2, and is now 4 in the new syllabus. This requires students to really have understood their organic transformations.
11: Measurements and data processing
- Here is the biggest change in this syllabus: spectroscopy is back in the core. Wonderful! The 2016-syllabus adds a section 11.3 to the core measurement topic, and includes the interpretation of mass spec, IR, and NMR.
- These used to be in Opt A, but the emphasis here is on the interpretation of spectra and seemingly all mentioning of instrumentation is out (along with theory of IR spectroscopy).
- Explicit in 11.3 is also the Index of Hydrogen Deficiency (IHD), which was an implicit skill in 2009-syllabus Opt A.
- For SL, the treatment of NMR spectra is restricted to integration and chemical shift; HL students would also make use of multiplicity (but not coupling constants).
- X-ray crystallography is also briefly introduced in the HL-extension 21.1.
The introduction of spectroscopy in the core would allow for more interesting spectroscopy questions, which is somewhat hamstrung when it was an option question (requiring a “fair” distribution with other option topics).
I haven’t thought through the options yet, though Opt B (biochemistry) looks largely similar to the current Opt B.
All in all, in terms of chemistry, the 2016-syllabus is deeper and tightly connects different topics, and would be instrumental in building better budding chemists. It also provides substantial help in connecting with other subjects (and ToK). I’m excited to teach it!
In the next part we look at the new internal assessment, completely overhauled, changes which I am far less enthusiastic about…
Edit 5 May 2014: updated with pointers to new terminology, from a list compiled by Catrin Brown.