How many atoms of sodium are there in 11.2 grams of sodium chloride?

Answer 1

This problem requires the atomic masses of each element involved. Then add them together to get the total molecular mass. If you take sodium's weight and divide it by the total mass, then you should have the percent of sodium in sodium chloride.

Na- 23.0

Cl- 35.5

NaCl- 58.5 grams

23.0 / 58.5 × 100= 39.3% Na in NaCl

Now we need to find the total number of atoms in the whole compound. Take the grams and convert it to atoms using Avogadro's constant.

11.2 g Na × (6.02 × 1023 atoms) / (23.0 g) Na = 2.93 × 1023 atoms

If that is the total mass, then we know that 39.3% of it has to be sodium

39.3% of (2.93 × 1023)= 1.15 × 1023 atoms Na