# Practice Empirical and Molecular Formula 1 For a

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Practice: Empirical and Molecular Formula 1. For a group of 2 or 3 2. Collect pens and a whiteboard! 3. Prepare yourself!

Q 1 EASY A compound contains 65. 66 % carbon, 15. 19 % hydrogen by mass and the rest nitrogen. Calculate the compound's empirical formula.

Q 2 MODERATE A small sample of antifreeze contains 4. 51 g C, 1. 13 g H, and 6. 01 g O. The molar mass is 62. 0 g/mol. Determine the empirical formula and the molecular formula.

Q 3 MODERATE/HARD A compound is 81. 7% carbon and 18. 3% hydrogen. a. What is its empirical formula? b. The formula weight of this compound is 352. 9 g/mol. What is the molecular formula?

Q 4 HARD Hemoglobin is the oxygen carrying compound found in human blood. It is found to contain 0. 3335% iron by mass. It is already known that one molecule of hemoglobin contains four atoms of iron. What is the molecular mass of hemoglobin?

Q 5 HARDEST! Calculate the molar mass of a metal that forms an oxide having the empirical formula M 2 O 3 and contains 68. 04% of the metal by mass. Identify the metal.

Chemistry 11 – Class Starter 1. Hebden: p. 95 Q’s 52, 54, 55 (Challenge Questions)

Finished…? 1. Hand the completed quiz at the front of the room 2. Collect the Lab: Dehydration of a Hydrate 3. Read the introduction, and use the handout to create your Pre-Lab which is due at the BEGINNING of next class