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Unformatted text preview: 0648 g of H.
(i) Determine the mass, in grams, of C in the 1.2359 g sample of the compound.
(ii) When the compound is analyzed for N content only, the mass percent of N is found
to be 28.84 percent. Determine the mass, in grams, of N in the original 1.2359 g sample of
(iii) Determine the mass, in grams, of O in the original 1.2359 g sample of the compound.
(iv) Determine the empirical formula of the compound.
(b) A different compound, which has the empirical formula CH2Br , has a vapor density of 6.00 g L− 1 at 375 K
and 0.983 atm. Using these data, determine the following.
(i) The molar mass of the compound
(ii) The molecular formula of the compound STOP
If you finish before time is called, you may check your work on this part only.
Do not turn to the other part of the test until you are told to do so. © 2006 The College Board. All rights reserved.
Visit apcentral.collegeboard.com (for AP professionals) and www.collegeboard.com/apstudents (for students and parents). 8 2006 AP® CHEMISTRY FREE-RESPONSE QUESTIONS CHEMISTRY
Time— 50 minutes
NO CALCULATORS MAY BE USED FOR PART B. Answer Question 4 below. The Section II score weighting for this question is 15 percent.
4. Write the formulas to show the reactants and the products for any FIVE of the laboratory situations described
below. No more than five choices will be graded. In all cases, a reaction occurs. Assume that solutions are
aqueous unless otherwise indicated. Represent substances in solution as ions if the substances are extensively
ionized. Omit formulas for any ions or molecules that are unchanged by the reaction. You need not balance the
Example: A strip of magnesium is added to a solution of silver nitrate. (a) Solid potassium chlorate is strongly heated.
(b) Solid silver chloride is added to a solution of concentrated hydrochloric acid.
(c) A solution of ethanoic (acetic) acid is added to a solution of barium hydroxide.
(d) Ammonia gas is bubbled into a solution of hydrofluoric aci...
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This note was uploaded on 10/01/2009 for the course OC 9876 taught by Professor Dq during the Spring '09 term at UC Merced.
- Spring '09