The equilibrium fraction of lattice sites that are vacant in electrum (a silver gold alloy) at 300K C is 9.93 x 10-8. There are 5.854 x 1015 vacancies/cm3.The atomic mass of electrum is 146.08 g/mol.Avagadro number 6.02210^23 atom/mol.Calculate the density of electrum in g/cm3.

Respuesta :

Answer:

the density of the electrum is 14.30 g/cm³

Explanation:

Given that:

The equilibrium fraction of lattice sites that are vacant in electrum  = [tex]9.93*10^{-8}[/tex]

Number of vacant atoms = [tex]5.854 * 10^{15} \ vacancies/cm^3[/tex]

the atomic mass of the electrum = 146.08 g/mol

Avogadro's number = [tex]6.022*10^{23[/tex]

The Number of vacant atoms = Fraction of lattice sites × Total number of sites(N)

[tex]5.854*10^{15}[/tex] = [tex]9.93*10^{-8}[/tex]  × Total number of sites(N)

Total number of sites (N) = [tex]\dfrac{5.854*10^{15}}{9.93*10^{-8}}[/tex]

Total number of sites (N) = [tex]5.895*10^{22}[/tex]

From the expression of the total number of sites; we can determine the density of the electrum;

[tex]N = \dfrac{N_A \rho _{electrum}}{A_{electrum}}[/tex]

where ;

[tex]N_A[/tex] = Avogadro's Number

[tex]\rho_{electrum} =[/tex] density of the electrum

[tex]A_{electrum}[/tex] = Atomic mass

[tex]5.895*10^{22} = \dfrac{6.022*10^{23}* \rho _{electrum}}{146.08}[/tex]

[tex]5.895*10^{22} *146.08}= 6.022*10^{23}* \rho _{electrum}[/tex]

[tex]8.611416*10^{24}= 6.022*10^{23}* \rho _{electrum}[/tex]

[tex]\rho _{electrum}=\dfrac{8.611416*10^{24}}{6.022*10^{23}}}[/tex]

[tex]\mathbf{ \rho _{electrum}=14.30 \ g/cm^3}[/tex]

Thus; the density of the electrum is 14.30 g/cm³