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Honors Chemistry
Unit 7 – The Mole Concept Review
1) Give the empirical formula for the following molecules:
a) C3H6
b) CH4
c) N2O6
2) How many molecules are in:
a) 2.0 moles of water
b) 21.9 grams of carbon dioxide
c) 58.2 grams of iron (III) acetate
3) How many grams are in:
a) 5.2 moles of nitrogen trioxide
b) 7.42 x 1024 atoms of gold
c) 3.194 x 1025 molecules of boron trichloride
4) What is the percent composition of the following:
a) NaOH
b) Ca(C2H3O2)2
c) Na3PO4
5) If 22.4 L is equal to 1 mole at STP what are the following conversions:
a) 3.67 moles of nitrogen (N2) to liters
b) 89.2 grams of oxygen (O2) to liters
c) 53.1 liters of Cl2 to grams
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Honors Chemistry
6) Calculate the molecular formula from the empirical formula:
a) HO is the empirical formula. The molecular formula is 34.02 g/mol
b) The empirical formula for a compound is CH. The molecular weight of the molecule is 78.12 g/mol
7) Mass of Hydrogen in 124 g of Ca(C2H3O2)2
8) Mass of Nitrogen in 378 g HCN
9) Mass of Oxygen in 100 g H2O
10) The compound meythl butanoate smells like apples. Its percent composition is 58.8% C, 9.8% H, and 31.4%
O. If its gram molecular mass is 102 g/mole, what is its molecular formula?
11) A compound of carbon and hydrogen has the composition of 92.25% carbon and 7.75% hydrogen by mass.
What is the empirical formula of this composition?
12) If the compound has a mass of 52.03 g/mole, what is the molecular formula of the compound?
13) A scientist reacts 2.15g of potassium with 0.88 grams of oxygen gas.
a) What is the percent composition?
b) How many moles of each element is present?
c) What is the empirical formula for the compound?
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