Question

how many moles of water, h₂o, contain 2.0 × 10²² molecules of water? (see the hints for assistance in
express the quantity in moles to two significant figures.
view available hint(s)
hint 1. tips for calculations involving scientific notation
hint 2. how to approach the problem
hint 3. state the given and needed quantities
hint 4. identify the conversion factor using avogadros number
hint 5. set up the problem to calculate the number of moles of h₂o

Explanation:

Step1: Recall Avogadro's number

Avogadro's number is $6.022 \times 10^{23}$ molecules/mol.

Step2: Calculate moles using conversion

Moles = $\frac{\text{Number of molecules}}{\text{Avogadro's number}} = \frac{2.0 \times 10^{22}}{6.022 \times 10^{23}}$

Step3: Simplify the expression

$\frac{2.0 \times 10^{22}}{6.022 \times 10^{23}} = \frac{2.0}{60.22} \approx 0.033$

Answer:

0.033