A Mathematical Anecdote Analogous to Chemical Resonance

What this little conundrum suggests is that in infinitely switching between two states, the final result is halfway in between. This is the reasoning behind the structure of benzene and the ionic carboxylate group.

s = 1 - 1 + 1 - 1 + ...

(-1) * s = (-1) * (1 - 1 + 1 - 1 + ...)   | *-1

1 + (-1) * s = 1 + (-1) * (1 - 1 + 1 - 1 + ...) | +1

1 - s = 1 - 1 + 1 - 1 + ...

1 - s = s

1 = 2 * s

s = 1/2


Source 

pH - Have you ever thought what it really is?

Most of us should know that the pH of a substance determines its acidity (or alkalinity). We know that both acids and alkalies are opposites of each other. An acid will react with an alkaline to neutralise it. pH is measured on the pH scale, with water being 'neutral'. However, have you ever thought what pH actually is?
In a nutshell, the pH of a substance measures how much a substance will dissociate when put in water.
This is when a hydrogen atom, attached by a covalent bond (shared electron) to a compound in an acid, breaks  free of the bond. However, with it breaking free it leaves behind its only electron: it is now a single proton with a positive charge. This little proton then attaches itself to a nearby water molecule (as the acid/alkali is in water) and forms the compound H3O. This is just water (H2O) with an extra hydrogen (H). Although the proton has now lost its electron it is still considered a Hydrogen molecule. The H3O ion (as it is now a positively charged particle - extra proton, but no extra electron) is extremely important, to the extent it has a special name of its own: hydronium. It is the measure of hydronium in a solution of an acid or base (which is an alkali dissolved in water) is rated on the pH scale. A low pH indicates there is a lot of hydronium, whereas a high pH indicates there is a smaller and smaller amount. Here's an example of an acid and water reaction, you can clearly see that H3O is left behind:
H2SO4 + H2O → H3O+ + HSO4−
The pH scale isn't just limited between 0 and 14, those are just the values which are naturally available, it can go above and below that into the minus numbers! However, if you have pure water, as much as you might like to think it is almost never pure. In fact, pure water self-ionises naturally over time. This is when one proton (hydrogen atom without its electron) transfers itself from one water molecule to another. This produces two oppositely charged ions and here is the equation:
H2O + H2O  H3O+ + OH−
However, water does not go on like this for ever, otherwise its pH would just keep falling! Eventually enough of it has undergone chemical change for it to be considerably less likely to react - a kind of equilibrium - the pH of that equilibrium just happens to be pH 7. That's why we call pH 7 neutral - its the pH of stability, and we base the scale around that.
So, any acid will naturally be a very good electrolyte (a substance which contains free ions, making it a good electrical conductor). This also explains why they use battery acid inside of batteries, as when the protons leave the acidic compounds, they make the compounds positive ions. Since electricity is the flow of charge (not electrons! That is just a very common method of transmitting charge) this means electric current can pass through!
If you have any questions please feel free to post below.

Air - The Thing Which Keeps us Alive Could Mean our Demise

Air is all around us all the time. It surrounds us every single minute of our lives, from start to finish: literally. Air is extremely important, and without it life may never even have come into existence. Air is mixture which helps us do things such as breathe, make fires and fly aeroplanes. One tiny change in the composition of air and we might have had very different lives, if none at all!  

A common misconception is that air is just one ‘element’. This is completely untrue! Air is not on the periodic table (you can check if you like). Air isn’t even one simple compound. In fact, air is actually a mixture of a variety of different elements and compounds in gaseous form, the most notorious of which being oxygen. However, this is not the gas in most abundance, in fact if it was we would most probably be dead, as pure oxygen is poisonous!

Air is actually made up mainly of nitrogen (around 78%), oxygen generally only makes up about 20-21% of air. There are also small amounts (around 1%) of noble gases such as argon and helium in the air. Finally, air contains substances essential for plant life: carbon dioxide (0.03%) and water vapour (0.97%, but it can vary!) Plants need carbon dioxide and water for the process of photosynthesis, where they convert these substances to glucose and oxygen in the process of photosynthesis. You may have heard of humidity levels. Since the amount of water in the air can vary, this can raise or drop humidity levels. It can go from 4% to 0.5%!

Air however does not only contain these set substances. It also contains minutely small amounts of other substances such as aerosols (which are tiny particles of dust from the ground or from volcanic ash.) If you can imagine zooming up into the sky, the composition of air there would be very different. There lies the notorious gas known as ozone, which environmentalists are currently making a big fuss about (due to the theory of global warming). There is also a lot more helium and hydrogen up there, as they are lighter elements, less dense than the others, so when they float up the others sink down.

You have probably heard of air pressure as well. This is just basically the weight of the air pushing down on everything on the earth – including us! Air pressure is measure in something called Pascal units which is just how many kilograms of ‘weight’/’force’ (measured in Newtons – “N”) act over 1 m² of area. So if 3kg of air was pressing down on 1 m² of area then the air pressure would be 3 Pascals. However the real pressure of the air comes nothing close to that. In fact for every 1 m² of area on the earth, air pressure results in a force equivalent to the weight of a large elephant pushing down on it! You may ask why we aren’t crushed by this force. This is because the blood in our bodies pushes out with an equivalent pressure and the two cancel out. This also explains why when we enter different areas of pressure, for example when flying on a plane, sometimes people get nosebleeds as the difference in pressure causes the blood vessels to expand and burst. Imagine if you entered a vacuum (space) without a special suit, you would just burst due to the pressure of your blood being too strong for your body to withstand!

Where does the energy come from in our food?

This may look fairly complicated, but actually its simply just the composition of the elements. Here it is in word equation form.

Although this may be slightly biology related it is also chemistry related AND physics related. So we know that when we eat food, to get energy we require the substance glucose (which is a molecule in the food we eat) to be burned in oxygen to produce carbon dioxide and water as by-products. However, most importantly this reaction produces energy, namely in the form of heat. Firstly here is the chemical equation:

C6H12O6 (aq) + 6O2 (g) → 6CO2 (g) + 6H2O (l) ΔHc -2880 kJ



Glucose + Oxygen → Carbon Dioxide + Water (+ENERGY:- 2880 kJ to be precise)

kJ or kilojoules are basically a unit to measure energy in (1000 joules, as the prefix "kilo" implies, as in kilometres or kilograms). You may have also heard of calories being used, especially in terms of food. They can be directly compared.

4.1868 kilojoules = 1 Calorie


One calorie is the energy needed to raise the temperature of exactly one gram of water by one degree Celsius. So, one kilojoule is just 1/4 of that amount of energy approximately.

So, anyway, we know that when these materials are transported to the cells, this chemical reaction occurs, producing heat energy. The equations are balanced. The question is, where did the heat energy come from?

We know that it is theoretically possible to convert matter into energy (as described by Einstein's equation of E=MC^2), but obviously no matter has been converted into energy for three reasons:-

• The equations are balanced
• You'd need immense heats for this to happen which we can't even produce on earth. Imagine this type of heat in your body!
• If we actually could produce anything close to these types of heat in our bodies, it wouldn't exactly be gaining energy would it?

So just what happens to release this energy?

This question can be answered simply if you know about atoms. Atoms always try to gain the lowest energy levels possible, as energy is stored in their chemical bonds, to keep them joined together in compounds. Glucose is fairly happy as glucose and oxygen is quite content with itself too. Unfortunately for them, when they come together, they realise that there is a another state they would prefer to be in, namely in the rearranged forms of water and carbon dioxide. You can of course probably guess why...

They need less energy!

Another law states that energy cannot be destroyed (although it can be theoretically created from matter). So where has all the excess energy gone that is not needed any more?

It's released as heat energy in your body!

So that answers the question of where the energy came from, but also describes sort of what chemical energy is, and how that becomes heat energy. If you have any questions or corrections, just leave them in the comments.