Life Sciences lab classes explained

In your next  107 practical   and  your next   109 maths workshop   you are going to be dealing with  concentrations ,  and after that concentrations are going to keep popping up, so it would be good for you to know about the various ways we can talk about concentration... Let's start with a definition: Concentration  = The amount of a specified substance in a unit amount of another substance There are various ways concentrations can be expressed.... 1. As the weight of something per unit volume For example,   grams per litre .   i.e.  20 grams per litre   (written as   20 g  l -1 ) means there are 20 grams of substance in one litre of solution. or  34 milligrams per litre   (written as   34 m g  l -1 ) means there are 34 milli grams of substance in one litre of solution  (this is the same as saying  0.034 grams per litre ) 2. As a percentage concentration...

Get those calculators at the ready, concentration and dilution calculations are coming up in practical 3. To help you along with these, I though I'd share with you my   top 3 all time favorite fantastic equations!   I hope you will enjoy and cherish them as much as I have! In no particular order.... If your mass is in grams, your moles will be in mol, if your mass is in mg, your moles will be mmol and so on - remember what your units are! Molecular mass  is the mass of one mole of something  (so if you have the same mass as the molecular mass of something, you will have one mole - look at the equation above and check this works!)   Molecular mass is often given to you, but if it isn't you can easily calculate it by adding up the relative atomic masses of all the atoms that make up the molecule you are dealing with.... Again, if your moles are in mol, your concentration will be in M, if your moles are in mmol, your concentration...