Answer:
3.01 × 10²³ molecules
Explanation:
To calculate the number of molecules in 16g of oxygen, we first have to find the number of moles of gas present.
The following formula must be used:
[tex]\boxed{\mathrm{no. \ of. \ moles = \frac{mass}{molar \ mass}}}[/tex].
A molecule of oxygen has a molar mass of 32 since one molecule comprises two oxygen atoms, each with a molar mass of 16. Therefore, using the above formula:
no. of moles = [tex]\frac{16}{32}[/tex]
= 0.5 moles
Now that we know the number of moles present, we can use the following formula to calculate the number of molecules:
[tex]\boxed{\mathrm{no. \ of \ molecules = no. \ of \ moles \times Avogadro's \ constant}}[/tex]
where Avogadro's constant = [tex]6.02\times10^{23}[/tex].
Using the formula above,
no. of molecules = [tex]0.5\times 6.02\times10^{23}[/tex]
= [tex]\bf3.01\times10^{23}[/tex] molecules
Therefore, there are 3.01 × 10²³ molecules in 16g of oxygen gas.
