Question

How many molecules are in 4.50 moles of H2O?
Responses

450 molecules
450 molecules

2.71 x 1024 molecules
2.71 x 10 24 molecules

3.00 x 1023 molecules

Answer 1

To find the number of molecules in 4.50 moles of H2O, you can use Avogadro's number, which is \(6.022 \times 10^{23}\) molecules per mole.

Here’s how to calculate it:

\[
\text{Number of molecules} = \text{moles} \times \text{Avogadro's number}
\]

\[
\text{Number of molecules} = 4.50 \, \text{moles} \times 6.022 \times 10^{23} \, \text{molecules/mole}
\]

Now, doing the multiplication:

\[
\text{Number of molecules} = 4.50 \times 6.022 \times 10^{23} \approx 2.71 \times 10^{24} \, \text{molecules}
\]

So, the correct answer is:

**2.71 x 10²⁴ molecules**.