Question

Calculate the mass(Info in figure)Please select either A,B,C, ir D afterwards.

Answer 1

To calculate the mass of BeI₂, we first need to convert it to number of moles using the Avogadro's number:

`n_(BeI_2)=(N_(BeI_2))/(N_A)=(3.6*10^(24))/(6.02*10^(23)mol^(-1))=0.5980\ldots*10^1mol=5.980\ldots mol`

Now we need to calculate the molar mass of BeI₂ using the molar masses of the atoms Be and I, which we can consult on a periodic table:

`\begin{gathered} M_(BeI_2)=1\cdot M_(Be)+2\cdot M_I \\ M_(BeI_2)=(1\cdot9.01+2\cdot126.90)g\/mol \\ M_(BeI_2)=(9.01+253.80)g\/mol \\ M_(BeI_2)=262.81g\/mol \end{gathered}`

And now we can calculate the mass:

`\begin{gathered} M_{BeI_(2)}=\frac{m_(BeI_2)}{n_{BeI_(2)}} \\ m_(BeI_2)=n_(BeI_2)\cdot M_{BeI_(2)} \\ m_(BeI_2)=5.980\ldots mol\cdot262.81g\/mol \\ m_(BeI_2)\approx1571.62g \end{gathered}`

Which corresponds to alternative A.