I am trying to figure out if the pH of 0.1 M acetic acid is equal to, greater than, or less than the pH of 0.1 M hydrochloric acid. I don't need someone to do the work for me, maybe just explain how to do it would be great, thanks alot! Devin
2007-07-10 15:30:55 · 6 answers · asked by Devin G 2 in Science & Mathematics ➔ Chemistry
0.1 M CH3COOH will have a higher pH than 0.1 M HCl.
The solution is fairly simple. The pH (power of H) of an aqueous solution is given by the formula:
pH = -log(H+),
where (H+) is the concentration of H+ ions.
Acetic acid CH3COOH is a weaker acid than hydrochloric acid HCl, so the 0.1 M solution of acetic acid would contain a lower concentration of H+ ions than the 0.1 M solution of hydrochloric acid. Therefore, if you plug in the numbers you will see that the pH of the acetic acid solution is higher than the pH of the hydrochloric acid solution. In other words, HCl is more "acidic" than CH3COOH.
1 tonne of feathers has the same mass as 1 tonne of bricks.
2007-07-10 15:40:16 · answer #1 · answered by minefinder 7 · 0⤊ 1⤋
The pH of acetic acid will be higher. Hydrochloric acid is one of the six common acids that is "strong", which means when put in water, 100% dissociation occurs, so that the [H+] is equal to the original concentration of the acid (for monoprotic acids).
Acetic acid is not one of the six, so it is classified as weak. Weak acids do not dissociate completely in solution, as so:
CH3COOH <----> H+ + CH3COO-
An equilibrium expression can be written for this reaction, with Ka being the equilibrium constant
Ka = [H+] [CH3COO-] / [CH3COOH]
For acetic acid, Ka = 1.8 * 10^-5, so the [H+] will be much less than 0.1 M. As pH = -log [H+], the pH for 0.1 M acetic acid will be higher than that of 0.1 M hydrochloric acid.
2007-07-10 15:43:05 · answer #2 · answered by TheOnlyBeldin 7 · 0⤊ 0⤋
The Ph of an solution is measured on a scale of 0 to 14. 0 to 7 is acidic and 7 to 14 is basic. 7 is netural and it's around water's ph. The lower is more acidic.
2007-07-10 16:08:04 · answer #3 · answered by lulu 3 · 0⤊ 0⤋
Acid always tends to have a lower pH level. I think the acetic acid would be equal to the hydrochloric acid because they have the same pH level. But, I could be wrong.
2007-07-10 15:35:05 · answer #4 · answered by Anonymous · 1⤊ 2⤋
Try using an indicator to find out the pH of each acid.
2007-07-10 15:58:47 · answer #5 · answered by Neilio 4 · 0⤊ 0⤋
hcl is a stronger acid (it is one of the 6 strong acids) than acetic acid so therefore it would have a lower pH regardless of the molarity.
2007-07-10 15:39:25 · answer #6 · answered by Kenny M 4 · 0⤊ 0⤋