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Ms. Huynh – Chemistry I
Name _____________________________ Period __________
Date _________
Test – The Mole Concept
Part I - Use factor label method. Every number must have units. Round answers to the correct number of
significant figures. (10 pts each)
1) 945 g of Pt = ? mol of Pt
answer with units_____________
2) 0.20 mol of Cu(NO3)2 = ? g of Cu(NO3)2
answer with units_____________
3) 8.5 x 1022 formula units of NaS2 = ? g of NaS2
answer with units__________
4) 3.65 mol of C2H4O2 = ? molecules of C2H4O2
answer with units_____________
Part II - Compute the followings: (10 pts each)
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5) What is the percentage composition of Al(PO3)3
6) What is the empirical formula of the compound with 32.38 % of sodium, 22.65 % of
sulfur, and 44.9% of oxygen?
7) What is the empirical formula of the compound with 12.37 g of potassium, 17.38 g of
manganese, and 20.25 g of oxygen.
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8) Find the molecular formula for the compound with a molar mass of 180 g/mol if it has
40% of carbon, 6.67 % of hydrogen, and 53.33 % of oxygen.
9) What percentage of water is found in CoCl2 · 6 H2O?
10)
What is the formula for a hydrate that is 86.7 g Mo2S5 and 13.3 g H2O?