Simplest (Empirical) Formula Directions

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Class Period:__________________

Simplest (Empirical) Formula

Directions:

Find the empirical formula for each of the compounds whose percentage composition is given below.

1.	88.8% copper; 11.2% oxygen	Answer: __________________
2.	40.0% carbon; 6.67% hydrogen; 53.33% oxygen	Answer: __________________
3.	70.0% iron; 30.0% oxygen	Answer: __________________
4.	10.1% carbon; 0.9% hydrogen; 89.1% chlorine	Answer: __________________
5.	12.6% hydrogen; 37.5% carbon; 50.1% oxygen	Answer: __________________
6.	60.2% terbium; 39.9% chlorine	Answer: __________________
7.	52.8% aluminum; 47.1% oxygen	Answer: __________________
8.	72.41% iron; 27.60% oxygen	Answer: __________________
9.	72.2% magnesium; 27.8% nitrogen	Answer: __________________
10	74.1% carbon; 8.6% hydrogen; 17.3% nitrogen	Answer: __________________

Simplest (Empirical) Formula - KEY
Directions:

Find the empirical formula for each of the compounds whose percentage composition is given below.

1.	88.8% copper; 11.2% oxygen	Answer: _____Cu2O_________
2.	40.0% carbon; 6.67% hydrogen; 53.33% oxygen	Answer: _____CH2O_________
3.	70.0% iron; 30.0% oxygen	Answer: _____Fe2O3 or (FeO2)_
4.	10.1% carbon; 0.9% hydrogen; 89.1% chlorine	Answer: _____CHCl3_________
5.	12.6% hydrogen; 37.5% carbon; 50.1% oxygen	Answer: _____CH3O or (H4CO)_
6.	60.2% terbium; 39.9% chlorine	Answer: _____TbCl3_________
7.	52.8% aluminum; 47.1% oxygen	Answer: _____Al2O3 or (AlO2)__
8.	72.41% iron; 27.60% oxygen	Answer: _____Fe3O4 or (FeO)__
9	72.2% magnesium; 27.8% nitrogen	Answer: ___Mg3N2__________
10	74.1% carbon; 8.6% hydrogen; 17.3% nitrogen	Answer: __C5H7N___________