Question

OK I FOUND A MISTAKE IN THE PH (ACID-BASE) METER SCIENTISTS INVENTED!!!

Answer 1

ok lets say i have 1L of water, and I ONLY PUTS 10^-9 mol of NaOH, well, this gives a pH of 5, but i mean WHHHHAAAATTT, how can it be acid if i put only base?? HELP PLZ??

Answer 2

o

Answer 3

the hydrogen concentration from water maybe is not neglected in this case

Answer 4

That has nothing to do with the pH-meter.

There are more hydroxide ions brought by water than by your tiny amount of added NaOH.

pH = 7.002 because

\([H_3O^+]=\Large \frac{\sqrt{c^2+4Kw}\;-\;c}{2}\)

where c is the concentration of added NaOH and Kw is ionic product of water

Answer 5

@Vincent-Lyon.Fr, does that mean if I have 1L of a 1mol/L concentrated NaOH solution. What this really means is that the 1mol of OH in this 1L of solution INCLUDES the number of OH that's made by water?

Answer 6

No because it means you have added one mole of NaOH to pure water.

For instance, there is only 1 mole of Na+ ions in you litre.
But there are slightly more OH- ions than 1 mol/L, but the difference is negligible.