Mole Conversions

Question

6. How many atoms are there in 1.68 x 10^-9 moles of lithium?

7. How many molecules are there in 4.55 g of nitrogen gas (N₂)?

8. How many molecules are there in 0.663 moles of water?

9. How many grams are there in 1.55 x 10²³ molecules of carbon dioxide?

10. How many atoms of nitrogen are there in 2.18 moles of nitrogen (N₂)?

11. How many moles are there in 1.326 x 10¹² molecules of carbon tetrachloride?

12. What is the volume occupied by 4.30 moles of oxygen gas (O₂) at STP?

Answer 1

6) Multiply by A = 6.022 x 10²³ particles -> 1.01 x 10¹⁵ atoms of Li.

7) Divide by molar mass 28.01g, then multiply by A -> 9.78 x 10²² molecules of N₂.

8) Multiply by A -> 3.99 x 10²³ molecules of H₂O.

9) Divide by A, then multiply by molar mass 44.01g -> 11.3g CO₂.

10) Multiply by A, then by 2 atoms/molecule -> 2.63 x 10²⁴ atoms of N.

11) Divide by A -> 2.202 x 10^-12 moles of CCl₄.

12) Multiply by 22.4 L for any gas at STP -> 96.3 L of O₂ at STP.