Assigments (Chapters 3-4): Stoichiomery and Chemical Reactions 2.1 Most combustion reactions occur in excess O2, that is, more than enough O2 to burn the substance completely Calculate the mass of CO2, in grams, that can be produced by burning 6.00 mol of CH4 in excess O2 2.2 A sample of commercial sulfuric acid is 96.4% H2SO4 by mass, and its specific gravity is 1.84 Calculate the molarity of this sulfuric acid solution 2.3 Calculate (a) the number of moles of H2SO4 and (b) the number of grams of H2SO4 in 500 mL of 0.324 M H2SO4 solution 2.4 Calculate the volume in liters and in milliliters of a 0.324 M solution of sulfuric acid required to react completely with 2.792 grams of Na2CO3 according to the equation H2SO4 + Na2CO3 - > Na2SO4 + CO2 + H2O 2.5 Find the volume in liters and in milliliters of a 0.505 M NaOH solution required to react with 40.0 mL of 0.505 M H2SO4 solution according to the reaction H2SO4 + NaOH - > Na2SO4 + H2O 2.6 We find that 22.3 mL of 0.240 M NaOH is required to react with a 50.0 mL sample of vinegar Calculate the concentration of acetic acid in the vinegar 2.7 a/ If it requires 50 ml of 0.030 M HCI to titrate a 00 ml sample of potassium hydroxide to the equivalence point, how many moles of potassium hydroxide are in the sample? b/ What was the original concentration of the potassium hydroxide? c/ What is the concentration of the potassium chloride salt at the equivalence point? 2.8 A solution of 37.12 ml of 0.1 51 M NaOH is required to neutralize a 20.00 ml sample of citric acid (H3C6H5O7)· H3C6H5O7 + NaOH > H2O + Na3C6H5O3 What is the molarity of the citric acid solution? Nguyen Tien Thao, Faculty of Chemistry, Hanoi College of Science, VNU 19 -Le Thanh Tong, Hanoi, Vietnam Email: nguyentienthao@gmail.com 2.9 Copper metal reacts with concentrated nitric acid to produce nitric oxide and copper nitrate Calculate the mass of nitric oxide produced when 5.00 of copper is consumed The unbalanced reaction is: Cu(s) + HNO3(aq) - > Cu2+(aq) + NO3-(aq) + NO(g) + H2O 2.10 How many milliliters of a 0.10 Mpotassium dichromate solution are required to titrate 50 mL of an acidic 0.1 M iron(lI) chloride solution? The unbalanced chemical reaction is: Fe2+ + H+ + Cr2O72- -Æ Cr3+ + Fe3+ + H2O Chemistry, Seventh Edition, Steven S Zumdahl University of Illinois Susan A Zumdahl University of Illinois Chapter 4, Exercises: 45, 47, 49, 51, 53, 55, 57, 59, 61, 63, 65, 67, 69, 71, 73, 75, 77, 89, 81, 83, 85, 87, 89 Nguyen Tien Thao, Faculty of Chemistry, Hanoi College of Science, VNU 19 -Le Thanh Tong, Hanoi, Vietnam Email: nguyentienthao@gmail.com