Key Worksheet - Chemical Reactions And Stoichiometry - With Answers PDF

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Stoichiometry Worksheet Key...

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SFSU Chem100 M. Corcoran Key Worksheet

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Chemical Reactions and Stoichiometry 1. Given the equation 3A + B → C + D, you react 1 mole of A with 3 moles of B. True or false: B is the limiting reactant because you have fewer moles of B than A. Answer: False

2. NaHCO3 is the active ingredient in baking soda. How many grams of oxygen are in 0.35 g of NaHCO3? a) b) c) d) ANS:

0.012 g 0.022 g 0.067 g 0.20 g d)

3. Suppose the reaction Ca 3(PO4)2 + 3H2SO4 → 3CaSO4 + 2H3PO4 is carried out starting with 103g of Ca 3(PO4)2 and 75.0 g of H2SO4. How much phosphoric acid will be produced? a) b) c) d) ANS:

74.9 g 50.0 g 112 g 32.5 g b)

Worksheet - Stoichiometry 4. When 125.0 g of ethylene (C2H4) burns in oxygen to give carbon dioxide and water, how many grams of CO2 are formed? a) b) c) d) ANS:

392.2 g 250.0 g 57.50 g 425.6 g a)

5. Consider the following reaction: CH4(g) + 4Cl2(g) → CCl4(g) + 4HCl(g) What mass of CCl4 will be formed if 1.20 moles of methane react with 1.60 moles of chlorine? a) b) c) d) ANS:

229 g 171 g 114 g 61.5 g d)

6. The Claus reactions, shown below, are used to generate elemental sulfur from hydrogen sulfide. 2H2S + 3O2 → 2SO2 + 2H2O SO2 + 2H2S →3S + 2H2O How much sulfur (in grams) is produced from 48.0 grams of O2? a) b) c) d) ANS:

16.0 g 32.1 g 48.1 g 96.2 g d)

Worksheet - Stoichiometry 7. How many grams of NaCl are contained in 350. mL of a 0.250 M solution of sodium chloride? a) b) c) d) ANS:

41.7 g 5.11 g 14.6 g 87.5 g b)

8. What mass of calcium chloride, CaCl2, is needed to prepare 2.850 L of a 1.56 M solution? a) b) c) d) ANS:

25.9 g 60.8 g 111 g 493 g d)

9. A 54.8 g sample of SrCl2 is dissolved in 112.5 mL of solution. Calculate the molarity of this solution. a) b) c) d) ANS:

0.346 M 3.07 M 3.96 M 8.89 M b)

Worksheet - Stoichiometry 10. What mass of NaOH is required to react exactly with 25.0 mL of 1.2 M H2SO4? a) b) c) d) ANS:

1.2 g 1.8 g 2.4 g 3.5 g c)

11. Consider the reaction between 15.0 mL of a 1.00 M aqueous solution of AgNO3 and 10.0 mL of a 1.00 M aqueous solution of K2CrO4. When these react, a precipitate is observed. What is present in solution after the reaction is complete? Note: the solid is not considered to be in solution. a) Ag+, NO3-, K+, CrO42-, water b) Ag+, NO3-, K+, water c) K+, CrO42-, water d) NO3-, K+, CrO42-, water ANS: d)

12. With what volume of 5.0 M HF will 7.4 g of calcium hydroxide react completely, according to the reaction 2HF + Ca(OH)2 → CaF2 + 2H2O? a) 20. mL b) 50. mL c) 30. mL d) 40. mL ANS: d)...