SigFig: 12.59

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Douglas Nguyen 2J
Posts: 71
Joined: Fri Sep 28, 2018 12:15 am

SigFig: 12.59

Postby Douglas Nguyen 2J » Sat Jan 19, 2019 8:21 am

The initial values given for the question were 0.0073 M of codeine and pKa of conjugate acid was 8.21. With that, I assumed there were 2 significant figures (0.0073).

The answer was: 1.5%, 3.96, 10.04
For 10.04, does ".04" count as two significant figures since it's after the decimal point? Or should it be 10.037 (this was the calculation I got), not counting the zero?

klarratt2
Posts: 60
Joined: Fri Sep 28, 2018 12:16 am

Re: SigFig: 12.59

Postby klarratt2 » Sat Jan 19, 2019 9:45 am

If 10.04 is a pH/pKa value, then it has 2 sig figs. For pH/pKa/pKb, sig figs are counted as the amount of numbers past the decimal. So 10.04 would be 2 sig figs and 10.037 would be 3 (you count the zero because it is between two nonzero numbers).


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