## calculation of ionisation percentage

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anto007
Sr. Member
Posts: 34
Joined: Tue Aug 10, 2021 10:13 am
Location: Italy

### calculation of ionisation percentage

Hi, could you help me with this exercise, please?
"The pH of a 0.6 M solution of a weak acid is 4.0. What is the percentage of ionised acid?"
Thanks.
The mind is like a parachute, it only works if it opens. -A. Einstein
ChenBeier
Distinguished Member
Posts: 974
Joined: Wed Sep 27, 2017 7:25 am
Location: Berlin, Germany

### Re: calculation of ionisation percentage

Calculate the Concentration of H+ of the acid from pH.
This value divide through the Concentration of the whole acid x 100% gives percentage of dissociation.
anto007
Sr. Member
Posts: 34
Joined: Tue Aug 10, 2021 10:13 am
Location: Italy

### Re: calculation of ionisation percentage

I did so:
pH= -log_10([H+])= 10^-4
%=((10^-4)/(0,6))*100=0,016

but I do not get the expected result (0.02%)
Should I round up?
The mind is like a parachute, it only works if it opens. -A. Einstein
ChenBeier
Distinguished Member
Posts: 974
Joined: Wed Sep 27, 2017 7:25 am
Location: Berlin, Germany

### Re: calculation of ionisation percentage

0,0166 % is correct
anto007
Sr. Member
Posts: 34
Joined: Tue Aug 10, 2021 10:13 am
Location: Italy

### Re: calculation of ionisation percentage

thanks
The mind is like a parachute, it only works if it opens. -A. Einstein