Sig Figs for pH
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Sig Figs for pH
Does anyone remember how to do sig figs for calculating pH? I think I remember Professor Lavelle saying it was different than the normal way of doing sig figs.
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Re: Sig Figs for pH
With pH, I believe that sig figs are only counted after the decimal. So a pH of 7.63 would be 2 sig figs.
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Re: Sig Figs for pH
If I remembered correctly:
Decimal places of a logarithm answer = significant figures of the number in log parenthesis.
Decimal places of a logarithm answer = significant figures of the number in log parenthesis.
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Re: Sig Figs for pH
For pH, the sig figs would start after the decimal point. If you have 3 sig figs going in, your answer should have 3 numbers after the decimal.
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Re: Sig Figs for pH
Hello! In regards to sig figs when calculating pH, it starts after the decimal point (ex: pH = 4.56 --> 2 s.f.). Hope this helps!
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Re: Sig Figs for pH
Calculating significant figures for pH is slightly different than that of regular significant figures. This is because for pH, only the digits after the decimal point are counted.
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Re: Sig Figs for pH
It depends on the significant figures of the concentration which will determine the digits of precision in the final answer.
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Re: Sig Figs for pH
I think the value with the least sig figs count towards your final sig fig count, and that sig figs only matter after the decimal point when it comes to PH, because the scale goes from 1-14, and because of that preciseness needs to be emphasized.
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Re: Sig Figs for pH
You basically just have to look at the mantissa (what follows the decimal point) and see how many significant figures there are after the decimal point after calculating the logarithm. This should match the number of sig figs in your input. So if you do log (1.5 * 10^2), it should equal 2.18 as there has to be 2 sig figs.
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Re: Sig Figs for pH
For pH and pOH sig figs you only count what is after the decimal. For example, a pH of 4.387 has three sig figs.
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Re: Sig Figs for pH
If your given three sig figs, the pH will have three decimal places because sig figs start after the decimal.
Re: Sig Figs for pH
Hello!
When determining the sig figs of pH, you should look at the numbers after the decimal.
EX: A pH of 4.782 would have 3 sig figs!
I hope this helped!
When determining the sig figs of pH, you should look at the numbers after the decimal.
EX: A pH of 4.782 would have 3 sig figs!
I hope this helped!
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Re: Sig Figs for pH
For pH, sigfigs are accounted for after the decimal spot. So if there are 4 significant figures, an example pH with correct sigfigs would be 3.2332
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Re: Sig Figs for pH
for pH, anything to the left of the decimal point does not count towards the # of significant figures.
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Re: Sig Figs for pH
With pH, the sig figs apply to anything after the decimal point. For example, if you want 3 sig figs, a potential pH would be 4.327
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Re: Sig Figs for pH
the amount of sig figs corresponds to the amount of decimal points I believe. For example if it is twi sig figs then there will be 2 decimal places.
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Re: Sig Figs for pH
For PH the amount of numbers after the decimal point are the number of sig figs in the value.
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Re: Sig Figs for pH
Significant figures work differently for pH. Unlike regular rules, significant figures for pH are counted after the decimal point.
So, a pH of 3.739 would be 3, not 4 significant figures.
So, a pH of 3.739 would be 3, not 4 significant figures.
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Re: Sig Figs for pH
Hello,
When talking about pH the sig figs start after the decimal point.
Hope this helps.
When talking about pH the sig figs start after the decimal point.
Hope this helps.
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Re: Sig Figs for pH
As added detail for the other answers, pH uses a different system to other sigfig conventions because of the logarithm function resulting in deviations at the decimal place equal to the amount of sig figs in the original number.
https://laney.edu/cheli-fossum/wp-conte ... r-logs.pdf
This website has good examples
https://laney.edu/cheli-fossum/wp-conte ... r-logs.pdf
This website has good examples
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Re: Sig Figs for pH
Honestly I don't worry too much about sig figs at least when it comes to achieve, but the generally rule of thumb is to follow your sig fig rules. When in doubt, I do 2 places after the decimal.
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Re: Sig Figs for pH
For pH, remember that sig figs are only counted after the decimal point (because of the logarithm).
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