2007-10-05 12:10:49 · 3 answers · asked by Anonymous in Science & Mathematics ➔ Chemistry
I know the answer is 994.613 but how many sig figs do I include in the answer?
2007-10-05 12:18:01 · update #1
One of your numbers only has 2 significant figures, (if there were four it would have been written as 2.900 mol) so, technically, your answer should only have 2 significant figures. Remember, your answer doesn't get "more exact" just because a calculator will give an answer out to 8 or 12 decimal places! On the calculator, you get 994.613 rounding off to 2 figures actually gets you to 990g (do not put in the decimal point or any zeros after wards or it will imply a higher degree of accuracy than is really the case. Note: some people round "up" if a number is 5 or larger, in that case, your answer would be 1000; but I'm not certian how you indicate that only 2 of the figures are significant (check you math or science text). I hope this helps.
2007-10-05 12:39:53 · answer #1 · answered by Flying Dragon 7 · 0⤊ 0⤋
Well since 1 mol of sucrose is 342.97, then all you gotta do is multiply that by the amount of mol you are given, in this case 2.9. So you got:
2.9mol*(342.97g/mol)=994.613g, you see that answer is right, cause the mols cancel each other and all you remain with is grams.
2007-10-05 19:16:40 · answer #2 · answered by NBL 6 · 0⤊ 0⤋
1 mole = 342.96 g/mol
2.9 mol x 342.96 g/mol = 994.613 g
Notice how the units cancel out. This is a good way to double check that your final answer is correct.
2007-10-05 19:15:55 · answer #3 · answered by Anonymous · 0⤊ 0⤋