Question 45 / 45:  Calculate (within a factor of 100) the number of water molecules in a fully grown human being. The mass of one water molecule is approximately 3 x 10-23 g and a human being may be considered to be 70% water.
A  $$10^{15}$$
B  $$10^{20}$$
C  $$10^{18}$$
D  $$10^{27}$$
E  $$10^{23}$$
<< First < Previous Next > Last >>
Explanation:

100 kg x 0.7 x 1000 g/kg x 1 mol/3x10-23 g = 2x1027

You may do this calculation in your head by just keeping track of the exponents.

Also, make sure that the units cancel appropriately in your expression for the final answer.

Quiz Home Page
https://www.jobilize.com/measurement-experimentation-lab-mcq-quiz-by-dr-steve-gibbs

Measurement & Experimentation Laboratory ME301

Author:

Access: Public Instant Grading

Attribution:  Dr. Steve Gibbs. Measurement & Experimentation Laboratory. The Saylor Academy 2014, http://www.saylor.org/courses/me301/
Ask
Copy and paste the following HTML code into your website or blog.
<iframe src="https://www.jobilize.com/embed/measurement-experimentation-lab-mcq-quiz-by-dr-steve-gibbs" width="600" height="600" frameborder="0" marginwidth="0" marginheight="0" scrolling="yes" style="border:1px solid #CCC; border-width:1px 1px 0; margin-bottom:5px" allowfullscreen webkitallowfullscreen mozallowfullscreen> </iframe>