I am trying to figure out an example in my chemistry book. The question says: How many atoms are in 3.3 X 10^ -(negative)3 of gold. I know that the conversion factor is (.0033/197) X 6.022 X 10^23. What I cannot figure out is that the book has an answer of 1.0 X 10^20 atoms Au. However, when I type in these numbers on my calculator I get 1.0 X 10^19 atoms Au. Can someone explain why the answer is what my book says it is? Thank you!
2007-12-18 12:41:00 · 4 answers · asked by Steven M 3 in Science & Mathematics ➔ Chemistry
0.0033 g / 196.97 = 1.675x10^-5 moles of gold
1.675x10^-5 x 6.022x10^23 = 1.009x10^19
or 1x10^19 atoms
I think your book has an error
2007-12-18 12:51:13 · answer #1 · answered by skipper 7 · 1⤊ 0⤋
Check the unit of measure of the gold. Is it in fact in grams or kilograms. Makes a difference because the gold is 197 grams/mol NOT kg/mol. If all the numbers are still correct, then there is a typo in the book.
2007-12-18 20:59:51 · answer #2 · answered by Charles M 6 · 1⤊ 0⤋
(3.3 x 10^-3)(6.022 x 10^23)/(1.97 x 10^2)=
10.09 x 10^18= 1.0 x 10^19
I get the same answer. Are you sure the original mass was in grams?
2007-12-18 20:52:14 · answer #3 · answered by Judi L 6 · 1⤊ 0⤋
Either your starting quantity is 33 mg (3.3*10^-2 g) or the answer in the book is in error.
2007-12-18 20:57:31 · answer #4 · answered by Helmut 7 · 1⤊ 0⤋