Like pH. If the concentration of a strong acid is 1M, the pH is zero. No unit, just zero. Where does the unit go?
2007-03-30 03:24:02 · 4 answers · asked by Christopher L 2 in Science & Mathematics ➔ Mathematics
just a theory if u get it
suppose concentration of H+=0.25M
[H+]=0.25*1M
pH= -log(0.25*1M)
= -[log0.25+log1M]
= -log0.25+0
(log1=0)
therefore no units
2007-03-30 03:37:49 · answer #1 · answered by Maths Rocks 4 · 1⤊ 0⤋
Think about what a logarithm is. It's the exponent to which you need to raise the base (either e or 10) to get the original number. To make sense, the original number has to be a ratio between physical quantities that have the same units, so the number on which you're taking the logarithm can't have units, either.
2007-03-30 10:35:27 · answer #2 · answered by Mark H 3 · 0⤊ 0⤋
To answer your pH question, pH isn't mol/L, it is actually the activity of hydrogen ions which is a dimensionless number. You approximate this activity with the mol/L measurement, so the logarithm you are taking is dimensionless to start with.
2007-03-30 10:37:53 · answer #3 · answered by cutesexyangelbabe 3 · 0⤊ 0⤋
A logarithm has no unit
2007-03-30 10:27:11 · answer #4 · answered by maussy 7 · 0⤊ 1⤋