Answer:
[tex]1.9 \times 10^{23} molecules[/tex] of [tex]PF_5[/tex] are found in 39.5 grams of [tex]PF_5[/tex].
Explanation:
Atomic weights : P= 31, F= 19,
molar mass of = 1 atomic weight of P+ 5 atomic weight of
F= 31+5 [tex]\times[/tex] 19
= 31+95
=126 g/mole
moles in 39.5 gm of
= [tex]\frac{Mass}{Molar mass}[/tex]
= [tex]\frac{39.5}{126}moles[/tex]
=0.3134 moles
1 mole of any substance contains
0.3131 moles contains 0.3134
[tex]= 1.9 \times 10^{23} molecules[/tex]
Therefore, [tex]1.9 \times 10^{23} molecules[/tex] of [tex]PF_5[/tex] are found in 39.5 grams of [tex]PF_5[/tex].
