Question

The number of atoms in 10.0 gram of CaCO3 (100.0g/mol) is?

Answer 1

n=m/M = 10 g / 100 gmol-1 = 0,1 mol
n=N/L --> N= n+L
N= 0,1 mol * 6,022*10^23mol -1 = 6,022*10^22 molecules

Answer 2

See I messed up on the first step. I used 10.0g and multiply that by 1molCaCO3/mass of CaCO3

Answer 3

you can also use simple equations and rearange them cause that way you make your life easier:
n1=m/M
n2= N/L
n1=n2
m/M=N/L
mL=NM
N=mL/M