Respuesta :
Answer:
Mass percentage of gold : 33.35%
Mass percentage of silver: 62.80%
Mass percentage of copper : 3.85%
Explanation:
[tex]N=n\times N_A[/tex]
Where : N = Number of atoms
n = moles
[tex]N_A=6.022\times 10^{23} [/tex] = Avogadro number
Let the total atoms present in the alloy be 100.
Atom percentage of silver = 44.9%
Atoms of of silver = 44.9% of 100 atoms = 44.9
Atomic weight of silver = 107.87 g/mol
Mass of 44.9 silver atoms = 107.87 g/mol × 44.9 = 4,843.363 g/mol
Atom percentage of gold= 46.3%
Atoms of of gold = 46.3% of 100 atoms = 46.3
Atomic weight of gold = 196.97 g/mol
Mass of 44.9 gold atoms = 196.97 g/mol × 46.3 = 9,119.711 g/mol
Atom percentage of copper = 8.8 %
Atoms of of copper = 8.8% of 100 atoms = 8.8
Atomic weight of copper = 63.55 g/mol
Mass of 44.9 copper atoms = 63.55 g/mol × 8.8 = 559.24 g/mol
Total mass of an alloy :4,843.363 g/mol + 9,119.711 g/mol + 559.24 g/mol
Mass percentage of gold :
[tex]\frac{4,843.363 g/mol}{4,843.363 g/mol + 9,119.711 g/mol + 559.24 g/mol}\times 100=33.35 \%[/tex]
Mass percentage of silver:
[tex]\frac{9,119.711 g/mol}{4,843.363 g/mol + 9,119.711 g/mol + 559.24 g/mol}\times 100=62.80\%[/tex]
Mass percentage of copper :
[tex]\frac{559.24 g/mol}{4,843.363 g/mol + 9,119.711 g/mol + 559.24 g/mol}\times 100=3.85\%[/tex]
