Q Unit 5 Exam • Points 100 • Submitting a file upload Here is the Unit 5 Exam. You can also find links to the Periodic Table, Common Ion List, and Solubility Rules and Electrolyte Strength Table. The Unit 5 Exam is a timed gated exam. To answer the questions, you can write on the .pdf with a touchscreen, you can print out the exam on paper and write in your answers, or you can write your answers on separate sheets of paper. Save your work as a .pdf, and submit your work using the Submit Assignment button at the top of the page. EXAM #5 - CHEM 305 - Summer 2021 Actions Periodic Table Actions Ion List Actions Solubility Rules and Electrolyte Strength Table Actions CHEMISTRY 305 - Introduction to Chemistry Unit 5 Exam – Chapters 13, 14, 16 Summer 2021 Semester Name:______________________________________ Last First Instructions: Make sure to follow the directions carefully In order to receive full credit, you must show your work. Round numerical answers to the correct number of significant figures. Include the proper unit in your answer if applicable. You may not use out-of-class sources during the exam. Your exam will not be graded unless it’s submitted before the deadline. Instructor: Darren J. Gottke Exam Score: 100 Points Total -1- SCORES: Page 3 Page 4 Page 5 Page 6 Page 7 Page 8 TOTAL SCORE -2- 1) Complete each statement by filling in the correct value or term in the blank provided. (9) a) Solutions must contain both solute and ______________________ in even distribution. b) A 10% m/m solution of LiOH in water has 10 g of LiOH dissolved into ___________ g of H2O. c) Polar liquids like alcohol are generally _______________________ in water. d) Decreasing the temperature of a solution will ________________ the solubility of a gas solute. e) Decreasing the gas pressure above a solution will ________________ the solubility of a gas solute. f) Ions with a higher charge are usually ________________ soluble in water than ions with a lower charge. g) Reactions that absorb energy from the surroundings are ______________________________. h) Arrhenius bases are compounds that release _________________ when dissolved in water. i) Strong acids like HCl will _____________________ almost completely when dissolved in water. 2) A solution is prepared by dissolving 1.775 g of K2CO3 into 165.5 g of water. Calculate the m/m % K2CO3 in this solution: (4) 3) Common intravenous (IV) glucose solutions are prepared as 5.0 % m/v glucose. How many grams of glucose are present in an IV bag that contains 1.50 Liters of solution? (5) -3- 4) A solution is prepared by dissolving 185 grams of NaC2H3O2 into water. The concentration of the solution is measured at 1.95 M. Calculate the volume (in Liters) of the solution: (5) (MM NaC2H3O2 : 82.03 g/mol) 5) A 0.575 L solution of NaOH dissolved in water is made to a concentation of 1.5 M NaOH. Another 3.15 L of water is then added to the solution. Calculate the NaOH Molarity of the diluted solution: (4) 6) Two solutions are prepared. The first contains the ionic compund Mg(NO3)2, dissolved in water at 1.160 M concentration. The second contains 83.0 grams of the covalent molecule glycol (C2H6O2), dissolved in water to a total volume of 0.411 Liters. (MM C2H6O2 = 62.08 g/mol) a) Calculate the Molarity concentration of the glycol solution: (4) b) Calculate the osmolarity concentration of both solutions: (2) c) Which solution would you predict to have the highest boiling point temperature? (2) -4- 7) Aqueous Aluminum chloride is combined with aqueous Lead (II) nitrate, and a precipitate forms according to the balanced chemical equation shown below: 2 AlCl3 (aq) + 3 Pb(NO3)2 (aq) º 2 Al(NO3)3 (aq) + 3 PbCl2 (s) Determine the volume (in L) of 0.484 M Aluminum chloride solution needed to react completely with 12.6 L of a 0.0500 M Lead (II) nitrate solution: (8) 8) Hydrobromic acid and Barium hydroxide react in the balanced chemical equation shown below: 2 HBr + Ba(OH)2 º 2 H2O + BaBr2 It takes 4.50 L of the HBr solution to react completely with 235 grams of Ba(OH)2. Calculate the Molarity of the HBr solution: (MM Ba(OH)2 = 171.36 g/mol) (8) -5- Reactants ProductsNRG Reaction Pathway 9) The reaction between ammonia and oxygen gas is an eqilibrium process, shown as an equation below. The reaction Keq = 2.2 x 1015 at 25°C. 4 NH3 (g) + 3 O2 (g) º 2 N2 (g) + 6 H2O (g) + heat a) Would this reaction be considered product-favored or reactant-favored at equilibrium? (1) b) Write out the equilibrium expression for this reaction: (3) Keq = c) Suppose some of the nitrogen gas was removed from the reaction after equilibrium is reached. Would this shift the reaction to the left, or to the right? (2) d) Suppose the equilibrium system was heated. How would this change the concentration of the oxygen gas? (2) e) Give the definition of the equilibrium point for a reversible reaction: (1) 10) Shown below is a reaction energy diagram. Answer the questions below using this diagram. a) Is this reaction exothermic or endothermic? ______________________ (1) b) Draw on the diagram how Activation Energy (EA) is measured. (2) c) Draw on the diagram how the Enthalpy (?H) is measured. (2) -6- 11) Circle the compounds shown below that are considered Arrhenius acids, and underline the compounds shown below that are considered Arrhenius bases. Do nothing to molecules that are neither acids or bases: (5) NaOH Pb(OH)4 LiH Pb(CO3)2 HNO2 (NH4)2CO3 H3PO4 HClO3 KClO3 Ca(CN)2 12) Consider the Brønsted-Lowry acid/base reaction shown below: (6) CO3 2 - (aq) + HF (aq) º HCO3 - (aq) + F - (aq) a) Which of these reactants / products is identified as the acid? _______ b) Which of these reactants / products is identified as the base? _______ c) Which of these reactants / products is identified as the conjugate acid? _______ d) Which of these reactants / products is identified as the conjugate base? _______ e) Give the definition of a Brønsted-Lowry acid: ______________________________ 13) The thiocyanate ion, SCN -, is considered a Brønsted-Lowry base. Write a chemical equation for the reaction of the thiocyanate ion with water: (4) 14) The molecule formic acid ( HCOOH ) is considered a Brønsted-Lowry acid. Write a chemical equation for the reaction of formic acid with the sulfate ion ( SO4 2- ): (4) -7- 15) A solution is created by dissolving 1.77 moles of HNO3 (a strong acid) into water, making 22.1 Liters of solution. Calculate the [H+] and the pH of this solution: (5) 16) What is the [H+] of an acid sample that has a pH of 0.230? (3) 17) What is the pH of an aqueous 0.00305 M KOH solution (a strong base)? (4) 18) What is the [OH-] of a blood sample that registers 7.42 on a pH meter? (4)