Question

Concerning these questions, would I multiplying by the mass of the element or would I just use 6.02 x 10^23.

1. If you have 5.62 moles of Be how many atoms of Be do you have?

2. If you have 7.89×10^23 atoms of Au , how many moles of Au do you have?

3. If you have 5.62 moles of Be how many grams of Be do you have?

4. If you 789 g of Au, how many moles of Au do you have?

Answer 1

Avogadro’s number is used to convert from moles to atoms/molecules. You can use the atomic mass/molecular mass to convert from mol to g and vice versa.
So, the best way that I have learned to do this is to use dimensional analysis, or just multiply by conversion factors x g/mol, 6.023*10^23 atoms/mol, etc.

Please let me know if you need any further clarification or explanation. And I’ll gladly double check your answers if you want me to.

Good luck, you’re gonna need it (not really, this stuff will be second nature before long)