please show how you got your answer using conversion

1. How many molecules are in 2.00 moles of H2O ? 2. How many moles are in 8.301023 molecules of H2O ? 3. How many molecules are in 0.50 moles of H2 ? 4. How many atoms are in 1.00 moles of He? 5. How many atoms are in 1.50 moles of Hg ? 5. How many molecules are in 2.50 moles of O2 ? 7. How many atoms are in 0.250 moles of Rb ? 8. How many moles are in 2.911022 atoms of He ? 9. How many moles are in 1.23105. molecules of H2 ? 10. How many moles are in 5.251025 atoms of Au? 11. How many moles are in 7.1:1035 molecules of O2 ? 12. How many moles are in 8.111020 molecules of CHi