5 posts • Page 1 of 1
For calculating logarithms/pH/pOH, the number of sig figs comes from the mantissa aka after the decimal place. However, for some problems (such as 12.27 and 12.29), the solutions manual does not acknowledge this. If the calculation was pH=-log(0.025) (2 sig figs), wouldn't the answer be 1.60 with the 2 sig figs shown in the decimal place?
1.60 actually has 3 sig figs, because all 0's after nonzero values after the decimal count as sig figs. I believe the correct answer would be 1.6, with 2 sig figs as was used in the original question.