Answer :
The elemental particles like the atoms, molecules and compounds present in a given substance is called an Avogadro's number. This number is expressed as [tex]N_{A}[/tex] and is equal to [tex]6.022 \times 10^{23} \;\rm mol^{-1}[/tex].
[tex]8.06 \times 10 ^{23}[/tex] molecules are present in 135 g of Teflon [tex]\rm C_{2}F_{4}[/tex].
How to calculate the molecules?
Given,
- Mass of the Teflon = 135 g
- The molecular weight of [tex]\rm C_{2}F_{4}[/tex] = 100.02 g/mol
We have 135 g, so moles will be:
[tex]\begin{aligned}\rm Moles (n) &=\dfrac{ \rm Mass }{\;\rm Molar \;\rm mass}\\\\\rm n &= \dfrac{135 \rm g }{100.02 \rm g/mol} \\\\\rm n &= 1.34 \;\rm mole\end{aligned}[/tex]
Hence,
1 mole contains [tex]6.022140857 \times 10^{23}[/tex] (Avogadro's number)
So 1.34 moles will contain,
[tex]\begin{aligned}&=1.34 \times 6.022140857 \times 10^{23}\\\\&= 8.06 \times 10 ^{23}\;\rm molecules\end{aligned}[/tex]
Therefore, [tex]8.06 \times 10 ^{23}[/tex] molecules are present in 135 g of Teflon [tex]\rm C_{2}F_{4}[/tex].
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