Recitation 3 UGA CHEM 1211 fillable PDF PDF

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Use as practice for upcoming tests and make sure you understand unit conversions to do well on the test. It's not...

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Recitation Worksheet 3

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1. If 5.0 mol hydrochloric acid and excess sodium sulfide are mixed and reacted according to the equation below, how many moles of hydrogen sulfide are produced? 2 HCl + Na2S → H2S + 2 NaCl

2.5

mol

2. What is the sum of the coefficients when this equation is balanced? 1 14 10 9 ________ C9H20 + ________ O2 → ________ H2O + ________ CO2

34

3. If 588 grams of FeS2 is allowed to react with an excess of O2 according to the unbalanced equation, how many grams of Fe2O3 are produced? FeS2 + O2 → Fe2O3 + SO2

782.6

g

4. When 8.00 x 1022 molecules of ammonia react with an excess of oxygen according to the chemical equation shown below, how many grams of nitrogen gas are produced? 4 NH3(g) + 3 O2(g) → 2 N2(g) + 6 H2O(g)

1.86

g

5. Sodium metal and water react to form hydrogen and sodium hydroxide. If 17.94 g of sodium react with water to form 0.78 g of hydrogen and 31.20 g of sodium hydroxide, what mass of water was involved in the reaction?

14.06

g

6. How many grams of calcium chloride are needed to produce 5.00 g of potassium chloride? CaCl2(aq) + K2CO3(aq) → 2 KCl(aq) + CaCO3(aq)

3.72

g

7. How many molecules of HCl are formed when 90.0 g of water reacts according to the following balanced reaction? Assume excess ICl3. 2 ICl3 + 3 H2O → ICl + HIO3 + 5 HCl

5.01*10^24

molecules

8. A compound has an empirical formula of CClH2, and its molar weight is 98.96 g/mol. What is the molecular formula of this compound? (list the atoms in this order C, Cl, H)

C2Cl2H4

9. What is the empirical formula for a compound if 300. grams of it are known to contain 82.4624 grams of Mo, 45.741 g of Cl, and the rest is bromine?

Mo2Cl3Br5

10. Determine the empirical and molecular formula for chrysotile asbestos. Chrysotile has the following percent composition: 28.03% Mg, 21.60% Si, 1.16% H, and 49.21% O. The molar mass for chrysotile is 520.8 g/mol.

Empirical formula

Molecular formula

Mg3Si2H3O8

Mg6Si4H6O1 6

11. Polymers are large molecules composed of simple units repeated many times. They often have relatively simple empirical formulas. Calculate the empirical formulas of lucite (plexiglas); 59.9% C, 8.06% H, 32.0% O.

C5H8O2

12. A commonly used yellow dye has a percent composition of 75.95% C, 17.72% N, and 6.33% H by mass with a molar mass of about 240 g/mol. Determine the molecular formula of the dye.

CHN5

13. Which pair of molecular formula and empirical formula is CORRECT? Molecular formula As2O5 SO2 C3 H6 C6H12O6 C12H26

A. B. C D. E.

Empirical formula AsO3 S2O4 CH3 CH2O CH2

B

14. What is the percent of carbon by mass in Vitamin E, C29H50O2?

80.9

%C...