Many of the reactions in Chemistry can be explained by reference to the bonds that exist between the relevant species, but some bonds are a bit more difficult to understand

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(Why cannot we human beings be like the lovely little creatures above!)

My underlying assumption in writing these blogs is that you have come here because you want some aspect of Chemistry explained to you. My blogs have therefore become longer in recent weeks because I am trying to explain things in greater depth. You can access my  books by going to the link “My Books” at the very top right of this webpage. Depending on what topic I am working on at the time, a Chapter in one of the two books will be updated almost every week during term time.

If you are in Year 13/the Upper Sixth, then this Autumn your life as a ‘child’ will come to an end and you will become an adult. The transition will be both daunting and at the same time exciting! During that transition you will inevitably make some mistakes (and I made many), but mistakes can be hugely helpful because if you are intelligent then you learn from your mistakes, and you then become a better person.

Here is a little trick that might help you in all your subjects (and not just in Chemistry)  –  and it will be especially valuable when you get to University or Med School/ Law School/ wherever. Create a “memory tree” for every important topic in every subject (cf. the Benzene memory tree in my Benzene blogs), and in the weeks leading up to the exams, twice a week go to bed early and spend three hours going through (in your head) every single memory tree in every single subject. The reason that some students do not get high grades is sadly NOT because they lack knowledge, but because they waste valuable time in trying to remember things that they could easily have memorised. For example, in 60 seconds can you tell me how to get from Benzene to an azo dye, and tell me ALL the reaction conditions that are needed for each of the four steps involved (and there is no thought process in this because all that it requires is recall from memory)? Now do you see what I mean! If you do not finish all the questions in an exam paper, then you just cannot get an A* or an A in the subject.

It is interesting that in 20 years of teaching ‘A’ Level Chemistry, only one of my students has gone on to read Chemistry at University, but almost all of my students have gone on to be extremely successful Doctors/Dentists/Lawyers/Engineers/etc. Chemistry as such has thus been absolutely unimportant to them! What is important is that it helped them to learn use their brains, and to demonstrate to prospective employers that they had decent brains and knew how to use them.

When you have left University/Med School/Law School/whatever, other than for having to put the details in a box on an Application form, I doubt that anyone will ever ask you what University you attended/what you read/and what Class of Degree you gained. However, what will be of interest to everybody will be how well you do your job  –  and your two years of ‘A’ Levels and your time at University will contribute hugely to that.

The Blogs

Last year (2018/19) I spent more time on Second Year Blogs than on First Year ones. This year (201920) I intend to reverse that process for the reason that if you have a good understanding of  the basics of Chemistry, then the complicated stuff will be a lot easier than if your foundations are weak/are shaky.  I am therefore going to start the year with telling you what I am trying to achieve.

Blogs to start the year

First Year Blog for 2019:20, 7th September 2019

A welcome to Upper Sixth:Y13 students, 7th September 2019

 

Blogs for the Summer hols

A Second Chance

Participants in the development of Molecular Biology, UK 1920-1970

Participants in the development of Molecular Biology, UK 1920-197

As those of you who are familiar with my blogs will know, I know a tiny bit of Chemistry, and a tiny bit of Maths, and I know very little about Physics and almost nothing about Biology  –  but in the course of the next few weeks/months it is my intention every weekend to try to make myself slightly more knowledgeable about “nucleosynthesis”. One of my heroes, Fred Hoyle, was one of the greatest Astrophysicists that this country has ever had, and he was the man who (post WWII) gave rise to our modern understanding of how the heavier elements were formed. His 1953 paper “On nuclear reactions occurring in very hot stars. I. The synthesis of elements from Carbon to Nickel” Astrophysical Journal Supplement, 1, p121-146 is not well known, nor is his 1960 paper with Fowler “Nucleosynthesis in Massive Stars and Supernovae”, The Astrophysical Journal,132(3), although his 1957 paper: Burbridge Burbridge Fowler and Hoyle “Synthesis of the Elements in Stars”,  Reviews of Modern Physics, 29(4), pp 547-650  is better known.  From some time after the end of WWII, in lectures given in the 1950s and certainly in the afore-mentioned papers, Hoyle showed that the heavier elements above Iron in the Periodic Table could not have been formed other than in collapsing supernovae provided that a supernova does not collapse into a ‘singularity’ (and this is what we laymen call a ‘back hole’).

Hoyle’s contribution to the understanding of the formation of the heavier elements followed on from the contribution of astrophysicists in the 1930s who had developed our understanding of the formation of elements in the fusion of everything inside an ordinary star (from Hydrogen onwards) until the formation of Iron  –  and from that point onwards (I think) it requires the temperatures and pressures generated by a collapsing supernova to form the heavier elements. I use the phrase “I think” because I am not a sufficiently competent physicist/mathematician to follow the arguments developed by Hoyle (and Fowler and the two Burbridges and Clayton).

My interest in the formation of the elements in stars was sparked by watching a BBC Four programme on the beginning and end of the Universe, and subsequent reading about the beginning of the Universe then led me to evidence put forward by Victor Alpher, in his paper “ Ralph A Alpher, George Antonovich Gamow, and the Prediction of the Cosmic Microwave Background Radiation”, Asian Journal of Physics, 23(1 and 2), 2014, that his father’s contribution to the understanding of CMBR had been unfairly attributed to George Gamow. My attention was immediately engaged because I am unhappy that the Nobel Prize for the discovery of Pulsars was incorrectly given to Hewish and Ryle when in fact it was the unbelievably modest Jocelyn Bell who actually discovered Pulsars (and the same unfairness can be seen in the treatment of Rosalind Franklin/Lise Meitner/et alii). I do hate it so when men (especially “Establishment” men) treat women badly. Such behaviour is so petty and so ungentlemanly. When I have done my research, and when I think that I have understood the historical sequence of events that unfolded, I shall put on this website a blog similar to the one “Participants in the development of Molecular Biology, UK 1920-1970” that I published some weeks ago.

I hope that you are all enjoying your Summer hols. In the Summer hol after I left school (1958) my best friend at school and I hitch-hiked round the whole of France stopping to work for three weeks in the hospitals in a place called Lourdes in the Pyrénées, and I loved every minute of my ‘rite of passage’! Sadly, hitch-hiking would be much too dangerous a thing for a teenager to do these days. When occasionally, while I am driving on a longish journey, I stop for a hitch-hiker, my grandchildren go ballistic and berate me for being so stupid and for taking such a risk. It is sad that we human beings can no longer rely on each other to behave well, and that being ‘nice’ to a stranger is considered too great a risk to take.

 

Previous Second Year ‘A’ Level Chemistry Blogs

Acids and Bases, 23rd March 2019a

Acids and Bases, 23rd March 2019b

Benzene, Part 1, 15th December 2018

Benzene, Part 2, 22nd December 2018

Benzene, Part 3, 29th December 2018

Benzene, Part 4, 5th January 2019

Calculation of pH values during a titration (a blog for Second Year ‘A’ Level students who are just about to sit their final exams), 30th March 2019

Carbonyl Compounds, Part 1 (Acids), 12th January 2019

Carbonyl Compounds, Part 2 (Aldehydes), 19th January 2019

Carbonyl compounds, Part 3 (Ketones), 26th January 2019

Chromatography, Second Year Blog for 11th May 2019

Equivalence Points, 23rd of March 2019

Electrophoresis and DNA Fingerprinting, 18th May 2019

Entropy, Second Year Blog, 1st June 2019

Halides and Sulphuric Acid, Second Year Blog, 4th May 2019

IR Spectroscopy, 27th April 2019

Kc : Ka : pKa : and Kw, Strong and Weak Acids, Second Year Blog for 18th May 2019

Kw equations to memorise for the exams, Year 2 Blog for 25th May 2019

Kw, The Ionic Product of Water Equilibrium constant, Year 2 Blog, 25th May 2019

Mass Spectroscopy, 20th April 2019

NMR:MRI Spectroscopy, Second Year Blog, 4th May 2019

Potassium Permanganate and Sodium Sulphite, Three reactions, 17th November 2018

Properties of Period 3 Elements and their Oxides, 1st December 2018

Signposts for alculating pH values in acid-base titrations

Sulphuric Acid and Halides, 9th March 2019

Transition Metals: Complexes, 24th November 2018

 

Previous First Year ‘A’ Level Chemistry Blogs

Acids and Bases, 23rd of March 2019

Calculations in Chemistry, Part 1, 23rd of February 2019

Calculations in Chemistry, Part 2, 2nd of March 2019

Calculations in Chemistry, Part 3, 9th of March 2019

Calculations in Chemistry, Part 4, 16th of March 2019

Colour Changes, 8th December 2018

Consequences of Bonding and Structure

∆H of Formation, 24th November 2018

Electrophilic Addition Reactions of Ethene, 10th November 2018

Fractional Distillation and Cracking, 1st December 2018

Ionic and Molecular substances, (The difference between), 2nd of March 2019

Isomerism, Cis:Trans, 3rd November 2018

Isomerism, Structural, 27th October 2018

Mass Spectrometry, First Year Blog, 20th April 2019

Melting Points and Boiling Points, Part 1, 2nd February 2019

Melting Points and Boiling Points, Part 2, 9th February 2019

Melting Points and Boiling Points, Part 3, 16th February 2019

Melting Points and Boiling Points, Part 4, 23rd of February 2019

Tests, 15th December 2018

Titration (the elements of), 9th March 2019

Yield, Atom Economy or Atom Efficiency, 8th December 2018