There are a few updated guides I have uploaded. The changes are only very minor and sometimes just formatting issues.
Good luck with the summer examinations.
There are a few updated guides I have uploaded. The changes are only very minor and sometimes just formatting issues.
Good luck with the summer examinations.
All the exam boards have published advanced notice of the major topics that will be covered in this years exams. These are meant to provide some help in preparing for the exams. I think the help that these give at A-level Chemistry is questionable. If you choose not to revise certain topics that are not on the major topics list, you could end up with a lower grade.
The key part of the guidance used is this phrase: “Topics not included on the list may still appear in multiple-choice items, questions with a low tariff, or via synopticity.” So any topic could appear on a multiple choice or as a minor part of a question on another topic. The difference in number of marks between a major topic and a low tariff topic is not specified- so potentially there could be anything up to 5 or 6 marks on a topic not listed. For example, with AQA, NMR does not feature on the major topics listed, but it is easy to add an NMR question worth a couple of marks onto almost any organic question- so you can be sure NMR will appear somewhere. Even if the major topics make up 80% of the marks, you cannot afford to throw away 20% of the marks if you want a high grade.
In addition, Chemistry is a subject that makes most sense when you have revised everything and make the connections between topics. If you take short cuts in your revision, you will be less able to answer the synoptic questions that range across topics.
So in conclusion, if you want a high grade and have a university place dependent on it, then my advice is revise everything to the same degree.
This resource is suitable for students at the end of their A-level studies wanting to practise using spectroscopy and reactions to work out the structure of organic compounds.
At the moment I have not uploaded the answers- just the questions. There are lots of questions though.
I have been doing a spring clean through both the GCSE and A-level guides. There are no major changes.
I have completed some updates to the A-level guides. Mostly the AQA ones. I will hopefully do some more major updates to OCR and EDEXCEL when I get some time to study the recent papers.
This is an update on a previously written blog post about some wider reading for Chemistry. I have added on several new books written in the last few years. The newer books are highlighted in bold. It is good to see a bumper selection of new chemistry popular science books. Some of these are a little harder to categorise as they take a broad sweep of chemistry, history and social issues.
Now that the chemistry exams are over and the long summer stretches ahead why not grab a chemistry book to deepen your knowledge a bit and find out something interesting. I don’t mean read a chemistry A-level text book but something a little different. Chemistry does not seem to get the same range of popular science books that Biology and Physics do, but there are some great books out there. The list contains books I know are in my school library but hopefully people not at Bancroft’s will find some of these books in your local/school/college library. Some of these books are no longer in print although they mostly have been published in the last ten years, so hopefully are not that hard to track down.
Books about Elements.
The first two in this elements list are big glossy ‘coffee table’ books with lots of oversized pictures and rather less text. They are undeniably attractive though. You will find a lot more text and interesting information in the Emsley and Parson books. Maybe get one with pictures and one with more text and then you get the best of both worlds.
You will find John Emsley appear several times on the list. He is a great writer of popular chemistry books. He writes about every day and unusual chemicals and mixes science with history and good stories. They are always great books that are easy to dip into. The Elements of Murder book just deals with a few highly poisonous elements used for dastardly purposes. If you can find ‘The shocking History of Phosphorus’ by him, do get it. It is a really interesting book about the element with arguably the most interesting history. It is unfortunately no longer in print and I don’t have it my school library.
‘Periodic tales :The Curious lives of Elements’, ‘The disappearing spoon’ and ‘Seven elements that have changed the earth ’ are a;; newer books that combine the chemistry with a broader sweep of the related history and politics and have lots of interesting stories.
Books about Molecules
These are books about interesting and common molecules. Again these are mostly popular science books that are easy to dip into. The ‘Molecules’ book by Atkins and ‘Stuff Matters’ are on the recommended reading list for Cambridge University Natural Sciences.
Stuff matters is more a materials science book but a great read with lots of chemistry.
General Chemistry readers
This list includes several books by Peter Atkins who is another prolific writer of both popular and academic chemistry books. The book ‘What is Chemistry?’ is quite short but is excellent. Well worth a read. It really gets to the most important features of the subject, and is more than accessible to an A-level student.
History of chemistry Books
These are books more about the history of the subject than the chemistry but obviously the chemistry features. The ‘Mendeleyev’s dream’ book is actually more about whole history of chemistry rather than just Mendeleyev. ‘The Periodic Table. Its story and its significance’ is an excellent history of the development of the Periodic Table. I seem to remember it argues that Mendeleyev’s work was based in many other scientists work rather than him being a lone visionary he is sometimes made out to be. Eric Scerri’s book ‘A tale of 7 elements’ is about the search for the seven missing elements such as Hafnium, Francium and Technetium that were 7 gaps in the late 19th century periodic table.
More advanced science Readers
These books are definitely not popular science books for a little light reading. The first two books are on the reading list for pre- Natural Sciences at Cambridge. If you are thinking about applying to do Natural sciences at Cambridge (on the physical side) then you ought to read ‘Why chemical reactions happen’. It is an excellent book that that really does explain why reactions happen. It is not an easy book though as it goes beyond A-level and introduces the ideas of Atomic and Molecular orbitals. Bright A-level students will cope though. It is important to read it from the start and read it all through. Don’t write it on your UCAS personal statement if you have not read it though. One of my ex-pupils who had read it was interviewed by Peter Worthers at his Cambridge interview and there were questions. (He got in!)
This applies to both A-level and GCSE. It is amazing how many marks are thrown away when writing about the collision theory.
Increasing temperature, concentration and surface area all increase the frequency of collisions.
It is not enough to say only there are more collisions as there is no reference to time.
More collisions per second is fine though.
A greater chance of collisions is not good enough as probability is not the same as frequency (This is sometimes accepted though.)
When talking about increased concentration then say there are more particles per unit volume.
More particles on its own is not good enough.
When talking about temperature the particles have more energy and move faster. They therefore collide more frequently. More particles will also collide with more energy than the activation energy. Leading to more successful collisions.
Be careful with activation energy. Sometimes candidates write particles have more activation energy. This is not correct though.
Activation energy is the minimum energy needed for the collision to be successful. Particles can’t have more or less activation energy. Particles can only have more or less energy than the activation energy. ( just two missing words completely changes the meaning)
If the particles have less energy than the activation energy they bounce off each other and do not react. If the particles have more energy than the activation energy then they react.
I have uploaded revised versions of the GCSE revision guides for AQA chemistry and trilogy. There are not major changes but I have made some improvements after looking at the first set of GCSE exams from last summer.
Find here
The golden rule in writing about bonding is to be clear about what particles are attracted to each other and what that attraction is.
Do not use the words atoms, ions, and molecules carelessly. A wrongly chosen word can throw away all your marks.
If a question is asking about the high melting point of magnesium oxide, a student will not get much credit for just saying it has strong bonds or strong ionic bonds.
A good answer might be: MgO has a giant lattice structure with strong electrostatic forces of attraction between oppositely charged ions. These require a lot of energy to break.
Similarly if talking about hydrogen bonding in ethanol it is essential to make to make it clear that you know it exists between ethanol molecules.
Statements like ethanol has hydrogen bonding, or contains hydrogen bonds are too vague, and potentially hint at a misunderstanding. Some students mistakenly believe the hydrogen bond in ethanol is the actual O-H covalent bond within the molecule. Any confusion with covalent bonds will result in losing all the marks in the question.
A good way of phrasing it is that ethanol forms hydrogen bonds between molecules.
I have updated most of the AQA , EDEXCEL and OCR guides. It is mostly minor formatting changes, correcting typos, changing spelling of sulphur to sulfur.