Help with Chemistry problems?

Question

I have 3 questions I need to finish.
One of them asks how many molecules are there in one mole? I'm not sure about that one but I put 6.23*10^23. Is that correct?
Quest. 2 says how many molecules are there in 444g of Li2CO3?
& #3- What is the mass (in grams) of 5.22*10^25 molecules of BaSO3?

Answer 1

1. 6.02 x 10 ^23 (Avogadro's number).
2. Divide 444 my the Mr of Li2CO3 and then multiply by Avogadro's number.
3. Divide the number of molecules by Avogadro's number and then multiply by the Mr of BaSO3.