Back MOLARITY OF SOLUTIONS 1. How many grams of Al2(SO4)3 will be required to prepare 300 mL of 0.200 M Al2(SO4)3? ans. 20.6 grams 2. If 12 grams of NaOH are dissolved in enough water to give 500 mL of solution, calculate the molarity of the solution. ans. 0.6 M 3. If 200 mL of 0.30 M Na2SO4 are evaporated to dryness, how many grams of dry sodium sulfate will be obtained? ans. 8.5 grams 4. What is the molarity of the sodium hydroxide in an alkaline solution which is 11% NaOH and the solution has a density of 1.23? ans. 3.4 M 5. In 3.58 M sulfuric acid solution there is 29.9% H2SO4 by mass. Calculate the density of the 3.58 M sulfuric acid solution. ans. 1.71 g/ml 6. A sodium sulfate solution's molarity has been determined to be 0.78 and a density of 1.12, what is the percent composition by mass of the sodium sulfate in the solution. ans. 9.9% 7.   10 cc of a 70.5% solution of sulfuric acid having a density of 1.61 g/mL were dissolved in enough water to give 25.0 cc of solution. What was the molarity of the final solution? ans. 4.6 M 8. How many moles of hydrogen will be liberated from 400 mL of 0.40 M HCl by an excess of zinc? ans. 0.08 moles 9. If 112.0 grams of NaOH were required to neutralize 82.0 mL of sulfuric acid, calculate the molarity of the sulfuric acid solution. ans. 17 M 10. How many mL of 0.25 M AgNO3 will be required to precipitate the chloride from 80.0 mL of 0.400 M NaCl? ans. 128 mL 11 The metabolism of glucose yields CO2 and water. Solid LiOH is used in space vehicles to absorb the carbon dioxide gas. How many grams of LiOH would be needed to absorb the carbon dioxide produced from the metabolism of 31 grams of glucose, C6H12O6 ? ___ C6H12O6 + ___ O2 ___ CO2 + ___ H2O ___ CO2 + ___ LiOH ___ Li2CO3 + ___ H2O ans. 49.6 grams 12. The distinctive odor of vinegar is due to acetic acid. Acetic acid reacts with barium hydroxide to produce water and barium acetate. What is the percent acetic acid , by weight, in the vinegar, if it takes 34.9 mL of 0.09 M Ba(OH)2 to react with the acetic acid in 5 mL of vinegar? The density of vinegar is 0.96 grams of vinegar per cc. ans. 7.8 %  13. The arsenic in a 1.22 gram sample of a pesticide is converted to AsO4-3 . The arsenate was then treated with silver nitrate as shown in the net ionic equation given below: ____ Ag+ + ____ AsO4-3 _____ Ag3 AsO4 If it took 25.0 mL of 0.102 M Ag+ to precipitate all of the arsenate, what was the percent arsenic in the pesticide? ans. 14. Federal regulations set an upper limit of 50 ppm of NH3 in the air in a work environment (parts per million, 50 mL of NH3 per 1 x 106 mL of air). The density of pure NH3(g) at room temperature is 0.771 grams per liter. Air from a manufacturing operation was drawn through a solution containing 100 mL of 0.0105 M HCl. The ammonia reacts with the hydrochloric acid as follows. NH3(g) + HCl(aq) NH4Cl(aq) It took 10 minutes drawing air containing the ammonia through the hydrochloric acid solution at a rate of 11 liters of air per minute, to consume all of the to consume all of the HCl(aq) . How many ppm of ammonia is in the manufactures air? Is the manufacturer incompliance with regulations? ans. 2100 ppm of ammonia TOP