Question

The balanced chemical reaction done by Mr. Ken is given below2 Na + Cl2 = 2 NaClIf 5.8*10^24 molecules of chlorine gas was present in the flask, how many moles of chlorine gas was used

Answer 1

To convert the number of molecules to number of moles, we can use the relation between mole and the number of molecules:

$1\text{ mole = 6}\times10^{23}\text{ molecules}$

In order to calculate the moles of chlorine gas (Cl2), we can use the following relation:

$\begin{gathered} 1\text{ mole of Cl2 ------ 6}\times10^{23}\text{ molecules of Cl2} \\ x\text{ moles of Cl2 ----- 5.8}\times10^{24}\text{ molecules of Cl2} \\ \\ x=\frac{5.8\times10^{24}}{6\times10^{23}}=\frac{5.8}{6}\times10^{24-23}=0.96\times10=9.6\text{ moles} \end{gathered}$

So, Mr. Ken has used 9.6 moles of Cl2.