# Mass-Mole conversion

1. Jul 3, 2009

### webz

1. The problem statement, all variables and given/known data
Show that 1kg of CaF2 equals 13 mol.

2. Relevant equations
Molar mass CaF2 = 78.074g/mol

3. The attempt at a solution
I can take 78.074g/mol CaF2 * 13 mol = 1014.962 g CaF2
But I can't do this equation backwards, I'm missing a step. I would think if I'm converting g/mol to mol, I would divide by how many grams I have (1000 in this case), but 78.074g/mol CaF2 / 1000g $$\neq$$ ~13mol.

Edit: I'm dumb. 1000/78.074 = ~13mol. Kill me now.

Last edited: Jul 3, 2009
2. Jul 3, 2009

### Staff: Mentor

You got it correctly on your own, there is still hope

Pay attention to units:

$$\frac {78 \frac g {mol}} {1000 g} = 0.078 \frac 1 {mol}$$

- and it is obvious what went wrong.