Units Cancellation Worksheet

Units cancellation worksheet 1.

1 dozen = 12 units 1 gross = 144 units 1 mole = 6.02 E 23 units = Avogadro’s Number

Elements are found on the periodic table. Zn Ag Na Mg

Compounds are different elements chemically bonded together. H2O FeCl3 K3N

The compound FeCl3 is 3 atoms of chlorine bonded to 1 atom of iron.

The atomic number is the number of protons in an atom. Every atom of hydrogen has exactly one proton. Every atom of neon has exactly 10 protons. Every atom of chlorine has exactly 17 protons.

The atomic mass is the weighted average of the protons and neutrons in an atom.

*** Conversion Factors ***

1 mole of hydrogen atoms has a mass of 1.01 grams and contains 6.02 E23 atoms.

1 mole of carbon atoms has a mass of 12.01 grams and contains 6.02 E23 atoms.

1 mole of oxygen atoms has a mass of 16.00 grams and contains 6.02 E23 atoms.

1 mole of water has a mass of 16.00 g + 1.01 g + 1.01 g = 18.02 grams and contains 6.02 E23 atoms of oxygen and 2* (6.02 E23) atoms of hydrogen for a total of 1.81 E24 total atoms.

The periodic table is a list of conversion factors for gram to mole conversions.

The metric system is a list of conversion factors.

A balanced equation is a list of conversion factors.

Atoms ↔ Moles ↔ Grams

Johnson S-08 Units Cancellation Worksheet 1 Name ______Set up problems only.

1. Convert 3.7 g of Zn to atoms.

2. Convert 36.1 grams of water to molecules.

3. Convert 8.20 E 36 atoms of Cu to grams.

4. Convert 98.1 grams of Na to moles.

5. Convert 5.95 X 1059 atoms of Fe to moles.

6. Propane is C3H8. If you have 7.42 E 54 molecules of propane, how many atoms of carbon do you have?

7. How many total atoms do you have in question 6?

Johnson S-08 8. 2H2 + O2 → 2H2O

How many molecules of water could be made from 345g of H2 and excess oxygen?

9. The density of water at 350C is 0.928 g per mL. How many g of water could you make in problem 8?

What volume in mL would this water occupy? In liters? In microliters? In nanoliters?

10. Hydrogen combines with nitrogen to form ammonia. 3H2 + N2 → 2NH3 How many grams is nitrogen would be required to produce 3.5 E6 grams of ammonia?

How many nitrogen molecules would be required?

How many nitrogen atoms?

Johnson S-08