-
Asked by flood2 to Cathal, Ciara, Emma, Michael, Sive on 13 Nov 2013.
-
Cathal Cummins answered on 13 Nov 2013:
Well, first things first, pH is a measure of how alkaline or acidic a solution is. But what does it mean for something to be acidic or alkaline? You can measure the acidity of a solution by measuring how many Hydrogen ions (Hydrogen atoms that have lost an electron) are kicking about in every litre of that solution; the more Hydrogen ions are there, the more acidic the solution is and the lower the pH of that solution.
So where does pH come from: it means “power of Hydrogen” since it is a measure of the amount of Hydrogen ions hanging around. The reason the word “power” is used has to do with maths — have you ever heard of something to the power of something else: like 2 to the power of 3 (it’s usually written as 2^3)? Well, it the same meaning as that … hope that helps! 🙂
-
-
Emma Cahill answered on 13 Nov 2013:
ha good question I learned something there, power of hydrogen!
thanks Cathal! -
Michael Nolan answered on 15 Nov 2013:
Hydrogen is very powerful indeed and will fuel your vehicle in the next couple of decades 🙂
pH is actually based on a logarithmic scale, which is useful to define a change in something that takes place over orders of magnitude (*e.g. from 10, to 1000 to 1000000 to 1000000000000) where the big numbers get hard to write out.
The idea is like the Richter scale: each increase of 1 is like a 10-fold jump in, say, activity or strength.
It is useful for a practical chemist to characterise the kind of solution they do an experiment in – so you can have molecules that like to pick up hydrogen to change an oxygen atom (-O) to an oxygen+hydrogen group (-OH). The pH of the solution will determine if you have the -O or the -OH and is important when describing experiments in water.
Comments