A quick sig figs question

[dekoyl]

I had thought that the answer to a question has the same number of sig. figs. as the least accurate piece of information in the question.

However, in this question, it gives three species, two of them are with 2 sig figs, one with 3 sig figs. In one part of the question, it requires each species' concentration to be calculated however answer to the species with 3 sig figs wants it in 3 sig figs.

Is this correct? Or should the answer have 2 sig figs?


Thanks you =]

[Rebecca.tutoring]

Not sure if I've 100% understood you, but do you you've got something like this?:

100mL 0.20M HCl; 20mL 0.3M NaOH; 22.5mL 0.35M HNO₃

If you had to find n(NaOH), it would be to ONE sig fig (0.006) because one of the species used in this particular calculation was only accurate to one significant figure: regardless of how many sig fig the other (irrelevant) pieces of information have.

The thing that is tripping you up is:

I had thought that the answer to a question has the same number of sig. figs. as the least accurate piece of information in the question.

Think of it in terms of the individual calculations - the number of sig figs in the solution to a calculation is the same as the number of sig figs in the least accurate piece of information in the species actually USED in that calculation.

[dekoyl]

Thanks a lot Rebecca =]