Answer to Question #12549 in Inorganic Chemistry for mass

Question

determine the number of atoms in each of the following
1) 2.85 mol of Ag
2) 12.9g of CaCO3
3) 12.9g of Fe(NO3)3

Answer 1

The number of particles is
N(particles) =
N(Avogadro)*n(particles)
1)
N(Ag) = 6.022*10^23 mol^-1 * 2.85 mol =
1.72*10^24
2)
The amount of CaCO3 is
n(CaCO3) = m(CaCO3) / M(CaCO3) =
12.9 g / 100 g/mol = 0.129 mol
N(CaCO3) = 6.022*10^23 mol^-1 * 0.129 mol =
7.77*10^22
3)
The amount of Fe(NO3)3 is
n(Fe(NO3)3) = m(Fe(NO3)3) /
M(Fe(NO3)3) = 12.9 g / 242 g/mol = 0.053 mol
N(Fe(NO3)3) = 6.022*10^23 mol^-1
* 0.053 mol = 3.19*10^22