# Question #a30bd

Apr 24, 2017

$1.61 \cdot {10}^{23}$ molecules of water.

#### Explanation:

This is a very simple chemistry question, and the explanation is as followed:

First, you want to calculate the molar mass of water. You can get the necessary information from the atomic weight of each element (see on the periodic table).
H2O = $\left(2 \cdot 1.01\right) + 16 = 18.02 \frac{g}{m o l}$

Now that you have found the molar mass, continue using dimensional analysis to find the answer. Also, note that I use the number $6.022 \cdot {10}^{23} \frac{a t m s}{m o l}$. This is Avogadro's number, and it will be very useful in chemistry.

$4.83 g \left(\frac{1 m o l}{18.02 g}\right) \left(\frac{6.022 \cdot {10}^{23} a t m s}{1 m o l}\right)$

All you have to do is plug this into your calculator, and you get
$1.61 \cdot {10}^{23}$ molecules of water in 4.83 g with three significant figures.