Weight Watchers

Chemistry's all about the little things, literally, its the study of individual molecules and the transfer of fundamental particles. But what happens when we want to use it in our own, considerably bigger world? So the question today is, how many molecules of sucrose (sugar) am I going to have to use in order to sweeten my tea?

In order to answer this question we're going to have to think back a bit, to the mid 1800s to be precise, before which chemists worldwide had pretty much just done their own thing as far as mass went. At this point it was getting too difficult to compare anything so it was decided that since oxygen reacted with so much, the relative atomic mass would be the mass relative to 1/16th of that of oxygen.

And it worked well, as far as they thought, but fast forward to 1912 and isotopes were discovered, atoms with different amounts of neutrons in the nucleus, which basically meant that nobody knew how much anything weighed anymore.

Eventually after another 50 years of scratching their heads, chemists worldwide decided to use carbon 12 as the standard, leading to the current definition as the mass relative to that of 1/12th of carbon 12.

But how did any of that relate to our scarily massive world I hear you cry, why was any of that even relevant? I'll tell you.

At this point everything was fine in the world of chemistry, and then possibly the most important unit in the world of chemistry was invented, the mole. The mole isn't like a standard unit, because its a number, 6.022x10²³ to be precise, because this is the number of atoms in 12g of carbon 12. This is also known as Avogardo's constant because although he did not discover it he did come up with the general idea.

From this we can figure out the mass and number of moles in a substance by knowing the other from a very simple equation, number of moles= mass/Relative atomic mass

Therefore if I use 2 spoons of sugar (approximately 8 grams) which has a general relative molecular mass of 342 by doing 8/342 I know I have 4/171 of a mole or 1.41x10²² molecules of sugar to make the perfect cuppa.

Hopefully this has helped you to see how much is beneath the surface of what we can simply see, I hope this blog inspires you to question everything, because the only people who make great strides are those who dare to question what they are told to take for granted. Thanks for reading :)