Question

multiple choice 1 point
how many molecules of water are in 1.8 moles of water?
1.6x10^25
1.1x10^24
1.6x10^(-24)
1.6x10^23

Explanation:

Step1: Recall Avogadro's number

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

Step2: Calculate number of molecules

Number of molecules = moles $\times N_A$. So, for 1.8 moles of water, the number of molecules is $1.8\times6.022\times 10^{23}$.
$1.8\times6.022\times 10^{23}=10.8396\times 10^{23}=1.08396\times 10^{24}\approx1.1\times 10^{24}$

Answer:

1.1x10^24 (corresponding to the second option)