pH Scale
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pH Scale
During lecture, Dr. Lavelle stated that it was uncommon, but there were instances where acids could have a pH lower than 0, or bases could have a pOH higher than 14. When would something like this occur?
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Re: pH Scale
I believe that an acid can actually have a negative pH when it yields a hydronium ion concentration greater than 1.0 M, because a solution whose hydronium ion concentration is equal to 1.0 molor would have a pH of 0.0.
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Re: pH Scale
a pH can be be below 0 in the case of superacids, where the chemical potential of protons is higher than it is in pure sulfuric acid. This causes the mixture to behave as if there is greater than a 1.0 molarity of Proton, for example 1.1. Taking the negative log of this molarity would result in a negative pH. However, I do not think we need to know the specifics for this class.
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Re: pH Scale
It is very rare for an acid or a base to stem away from the normal range of 0-14, but it is possible for a very strong acid to have a negative pH and it is also possible for a very strong base to have a pH over 14.
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Re: pH Scale
Hi Tiahna,
In addition to what others have said, an example of an acid with a calculated pH lower than 0 would be 12M hydrochloric acid, which is calculated to have a pH of -1.08. On the other hand, an example of a base with a pH higher than 14 would be sodium hydroxide, which can have a calculated pH of 15.
I hope this helps!
In addition to what others have said, an example of an acid with a calculated pH lower than 0 would be 12M hydrochloric acid, which is calculated to have a pH of -1.08. On the other hand, an example of a base with a pH higher than 14 would be sodium hydroxide, which can have a calculated pH of 15.
I hope this helps!
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Re: pH Scale
Hello!
It is uncommon pH level to be below 0 and pOH to be above 14. However, it is possible in situations where there are very strong acids and bases. Hydrochloric acid is an example that proves this. Hope this helps!
It is uncommon pH level to be below 0 and pOH to be above 14. However, it is possible in situations where there are very strong acids and bases. Hydrochloric acid is an example that proves this. Hope this helps!
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Re: pH Scale
The pH scale should be between 0 and 14, and it is rare for a solution to have pH below zero.
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Re: pH Scale
Yes it is rare but off the scale pH values occur when the concentration of OH- or H+ is greater than 1M
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Re: pH Scale
Though not seen too often, it is possible for an acid to have a negative pH value and a base to have a pH greater than 14. Hydrochloric acid is a good example of this. If you have 12M HCl, the pH calculation ends up being -1.08.
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