Question

2 gram of substance contains 5x10^22 molecules
calculate the moleculler mass​

Answer 1

You can't just look at the solution and figure it out. Counting molecules in a solution isn't as simple as counting jelly beans in a jar. You can't even pop a sample of the solution under a light microscope to try and see the molecules. They're simply too small!

Then how can you account for how many salt molecules there are? The key is Avogadro's number.