That much sodium nitrate contains
Since sodium nitrate is an ionic compound, you can't really say that you're dealing with molecules, but with formula units.
In order to calculate how many formula units a certain mass of a substance contains, you need to do two things
- determine how many moles are present in that many grams by using the substance's molar mass;
- determine how many formula units you have in that many moles by using Avogadro's number.
So, use sodium nitrate's molar mass to determine how many moles are present in 2 g
Avogadro's number tells you that 1 mole of any substance contains exactly
This means that you have