Question

how many atoms are in 1.50 moles of fluorine gas?
a 18.98
b 6.022 × 10²³
c 1.81 × 10²⁴
d 9.03 × 10²³

Explanation:

Step1: Determine the molecular formula of fluorine gas

Fluorine gas is \(F_2\). One molecule of \(F_2\) contains 2 atoms of fluorine.

Step2: Use Avogadro's number

Avogadro's number \(N_A = 6.022\times10^{23}\) molecules/mol.
First, find the number of \(F_2\) molecules in 1.50 moles: \(N_{F_2}=n\times N_A\), where \(n = 1.50\) mol. So \(N_{F_2}=1.50\space mol\times6.022\times 10^{23}\space molecules/mol = 9.033\times 10^{23}\space molecules\).
Then, find the number of fluorine atoms. Since each \(F_2\) molecule has 2 F atoms, \(N_{F}=2\times N_{F_2}\).
\(N_{F}=2\times9.033\times 10^{23}=1.8066\times 10^{24}\approx1.81\times 10^{24}\) atoms.

Answer:

C. \(1.81\times 10^{24}\)