chemistry (molecular calculations)
posted by Eliza on .
If you had 106.35 grams of Cl, how much Na would be required to convert i all to NaCl. I worked this problem and got 41.83 grams of Na, but I'm not sure if this is correct.

The quick way is to use a chemical factor but that isn't taught anymore in chemistry classes. It would be
106.35 x (atomic mass Na/atomic mass Cl) = 69.00 g Na.
The modern, and long way around is this.
(106.35/atomic mass Cl) = mols Cl
Convert to mols Na by
mols Cl x (1 mol Na/1 mol Cl)
Convert mols Na to g Na by
g Na = mols Na x (atomic mass Na/1 mol Na)
Put together this becomes
(106.35g/atomic mass Cl) x (1 mol Na/1 mol Cl) x (atomic mass Na/1 mol Na) =
(106.35/35.45) x (1/1) x (23/1) = 69.00