Answer:
2.0*[tex]10^{17}[/tex]
Explanation:
Let us calculate total moles (air + CO)
moles (n) = PV /RT
P = 755 torr/760 = 0.9934 atm
V = 1.00 L
R = gas constant
T = 23°C + 273 = 296 K
So,
total moles (n) = 0.9934 x 1.00/0.0821 x 296 = 0.041 moles
mole fraction of CO = 8.1 x [tex]10^{-6}[/tex]
moles of CO =8.1 x [tex]10^{-6}[/tex] *0.041
=3.31 x [tex]10^{-7}[/tex] moles
number of molecule of CO =3.31 x [tex]10^{-7}[/tex] *(6.0233x [tex]10^{23}[/tex])
= 2.0*[tex]10^{17}[/tex]
