College Physics (4th Edition)

Published by McGraw-Hill Education
ISBN 10: 0073512141
ISBN 13: 978-0-07351-214-3

Chapter 13 - Problems - Page 498: 35


There are $2.65\times 10^{25}$ hydrogen atoms.

Work Step by Step

A carbon atom consists of 6 protons and 6 neutrons. A hydrogen atom consists of 1 proton. An oxygen atom consists of 8 protons and 8 neutrons. We can find the mass of one molecule of sucrose: $(12)(12~u)+(22)(1~u)+(11)(16~u) = 342~u$ The fraction of a sucrose molecule's mass that is hydrogen is $\frac{22~u}{342~u} = 0.0643$ We can find the mass of the hydrogen in 684.6 grams of sucrose: $m = (0.0643)(0.6846~kg) = 0.044~kg$ We can find the number of hydrogen atoms: $\frac{0.044~kg}{1~u} = \frac{0.044~kg}{1.66\times 10^{-27}~kg} = 2.65\times 10^{25}$ There are $2.65\times 10^{25}$ hydrogen atoms.
Update this answer!

You can help us out by revising, improving and updating this answer.

Update this answer

After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.