THE MOLE CONCEPT

1 mole = 6.022 x 10²³ particles

1 mole = molar mass (could be atomic mass from periodic table or molecular mass)

Remember:

Write your starting amount and unit over one.

Set up the rest of the conversions in order to cancel out the UNITS. Do not write the numbers in until you have the units in order.

Fill in the numbers for the conversion factors according to where you placed the units.

Adjust your answer for significant figures and check for the correct unit.

Check to make sure your answer makes sense.

11. How many oxygen molecules are in 3.36 g of oxygen gas (O₂)?

12. Determine the moles and number of atoms of 14 g of nitrogen gas (N₂).

13. Find the mass, in grams, of 1.00 x 10²³ molecules of (NH₄)₂SO₄.

14. How many ¹²C atoms are present in a mole of ¹²C ?

15. How many molecules of cinnamic alcohol (C₉H₁₀O) are contained in a sample of mass 0.469 g?

16. How many grams are in 8.2 x 10²² molecules of N₂I₆?

17. How many moles are in 3.45 x 10²³ molecules of H₂CO₃?

18. Aspartame is an artificial sweetener that is 160 times sweeter than sucrose (table sugar) when dissolved in water. It is marketed as NutraSweet. The molecular formula of aspartame is as follows: C₁₄H₁₈N₂O₅

a) Calculate the molar mass of aspartame.

b) How many moles of molecules are in 20.5 g of aspartame?

c) What is the mass in grams of 3.56 moles of aspartame?

d) How many molecules are in 8.3 g of aspartame?