Respuesta :
Explanation:
It is known that volume of a cylinder is as follows.
Volume of cylinder = [tex]\pi \times r^{2} \times h[/tex]
= [tex]3.14 \times \frac{1.26}{2} \times 7[/tex]
= 8.72 [tex]cm^{3}[/tex]
Therefore, mass of [tex]P_{4}[/tex] = [tex]density \times volume[/tex]
= [tex]1.823 g/cm^{3} \times 8.72 cm^{3}[/tex]
= 15.90 g
As, number of moles of a substance equals its mass divided by its molar mass.
Hence. No. of moles of [tex]P_{4} = \frac{mass}{\text{molar mass}}[/tex]
= [tex]\frac{15.90 g}{123.89 g/mol}[/tex]
= 0.1283 mol
According to moles concept, in one mole there are [tex]6.022 \times 10^{23}[/tex] atoms.
Hence, in 0.1283 mol number of atoms of [tex]P_{4}[/tex] are calculated as follows.
Molecules of [tex]P_{4} = 0.1283 \times 6.022 \times 10^{23}[/tex]
= [tex]0.772 \times 10^{23}[/tex] molecules
= [tex]7.72 \times 10^{22}[/tex] molecules
Therefore, atoms of P are calculated as follows.
[tex]4 \times 7.72 \times 10^{22}[/tex] molecules
= [tex]3.09 \times 10^{23}[/tex] atoms
Thus, we can conclude that total number of [tex]P_{4}[/tex] atoms are [tex]3.09 \times 10^{23}[/tex].
