To determine how many molecules are in 4 moles of [tex]\( H_2O \)[/tex], we can use Avogadro's number, which tells us the number of molecules in one mole of any substance. Avogadro's number is [tex]\( 6.02 \times 10^{23} \)[/tex] molecules per mole.
Here is the step-by-step solution:
1. Identify Avogadro's number:
Avogadro's number [tex]\( N_A \)[/tex] is [tex]\( 6.02 \times 10^{23} \)[/tex] molecules per mole.
2. Identify the number of moles:
We are given 4 moles of [tex]\( H_2O \)[/tex].
3. Calculate the number of molecules in the given moles:
Multiply the number of moles by Avogadro's number.
[tex]\[
\text{Number of molecules} = \text{Number of moles} \times N_A
\][/tex]
For 4 moles of [tex]\( H_2O \)[/tex]:
[tex]\[
\text{Number of molecules} = 4 \text{ moles} \times 6.02 \times 10^{23} \text{ molecules/mole}
\][/tex]
4. Perform the multiplication:
[tex]\[
4 \times 6.02 \times 10^{23} = 2.408 \times 10^{24}
\][/tex]
So, the number of molecules in 4 moles of [tex]\( H_2O \)[/tex] is [tex]\( 2.408 \times 10^{24} \)[/tex].
The correct answer is:
B. [tex]\( 2.408 \times 10^{24} \)[/tex]