Name: Teacher: DO NOT OPEN THE EXAMINATION PAPER UNTIL YOU ARE TOLD BY THE SUPERVISOR TO BEGIN O'DONEL HIGH SCHOOL MIDYEAR EXAMINATION CHEMISTRY 2202 SAMPLE (Revised January 2015) Value: 100% Time: 2 hours General Instructions This examination consists of two parts. Both parts are contained in this booklet and further general instructions are provided on appropriate pages. Section I - Multiple Choice - 35 Questions - (50%) Shade the letter of the correct answer on the computer scorable answer sheet provided. Do ALL questions in this section. Section II - Extended Response - (50%) Answer ALL questions fully and concisely in the space provided. Show all math work, and use correct units and significant digits in all final answers. Student Checklist The items below are your responsibility. Please ensure that they are completed. Write your name and teacher's name on the top of this page. Write your name, your teacher's name and the course name and number on the machine scorable sheet. Check the exam to see that there are no missing pages. ALL MATERIALS MUST BE PASSED IN with this exam. Use your time wisely. Good luck.
Page 1 of 8 Chemistry 2202 Sample Midyear Exam Section I Multiple Choice (35 questions, 50%) Place the correct answer to the following multiple choice on the answer sheet provided. 15 1. How many neutrons are in N? A. 7 B. 8 C. 14 D. 15 2. How may the mole be defined? A. 6.02 particles of any substance. 23 B. 1 x 10 particles of any substance. C. 19g of fluorine-19 D. 12g of carbon-12 3. How many molecules are in 34.0mol of sulfur trioxide, SO 3? 25 A. 2.05 x 10 molecules -23 B. 5.65 x 10 molecules 22 C. 1.77 x 10 molecules D. 34.0 molecules 4. What is the molar mass of (NH 4) 2SO 4? A. 228.34 g/mol B. 132.17 g/mol C. 118.15 g/mol D. 116.13 g/mol 24 5. How many moles are in 4.81 x 10 atoms of lithium, Li(s)? A. 0.125 mol B. 7.99 mol 48 C. 2.90 x 10 mol 23 D. 6.93 x 10 mol 6. What is the volume of 3.20mol of carbon dioxide gas, CO 2(g), at STP? A. 71.7L B. 0.140L C. 7.00L D. 141L 7. How is the molar mass of SO 2(g) correctly described? A. the number of particles in a mole of sulfur dioxide molecules B. the number of litres in a mole of sulfur dioxide molecules C. the number of grams of one mole of sulfur dioxide molecules D. the ratio of sulfur to oxygen atoms in one mole of sulfur dioxide 8. What is the mass of 2.40mol of sodium hydroxide, NaOH? A. 48.0 grams B. 16.7 grams C. 96.0 grams D. 0.0600 grams 2 9. How many moles are in 79.3g of chlorine gas, Cl (g)? A. 0.894mol B. 0.447mol C. 2.24mol D. 1.12mol
Page 2 of 8 10. Which term describes "a solution that contains the maximum amount of solute for a given amount of solvent"? A. unsaturated B. saturated C. supersaturated D. dynamic 11. How many moles of solute are in 300.mL of 3.00mol/L sodium chloride, NaCl? A. 0.100mol B. 10.0mol C. 0.900mol D. 900.mol 12. A sample of a pure compound contains 12.50g of Zn and 17.50g of Br. What is the percent composition of zinc in the compound? A. 58.33% B. 41.67% C. 71.42% D. 28.57% 13. How many moles of oxygen gas are contained in a volume of 112L at STP? A. 3.50mol B. 5.00mol C. 7.00mol D. 0.200mol 14. What is the percent composition of carbon in oxalic acid, H2C2O 4? A. 1.12% B. 2.24% C. 13.3% D. 26.7% 15. How many grams of hydrogen are in 75g of water, H2O? A. 4.2g B. 8.4g C. 6.7g D. 0.24g 16. Which is an empirical formula? A. C6H6 B. C3H8 C. C3H6 D. C H 4 10 17. What is the meaning of the term aqueous? A. a substance is in the liquid phase B. a substance is dissolved in water C. a substance is not very soluble in water D. a substance is reactive with water 18. Which compound will not dissolve in water? A. sodium bromide, NaBr B. calcium nitrate, Ca(NO 3) 2 C. calcium sulfate, CaSO 4 D. ammonium carbonate, (NH ) CO 4 2 3 19. Sucrose is dissolved in water to make cooking syrup. Which term defines the role of sucrose in this situation? A. solute B. solution C. solvent D. saturate
Page 3 of 8 20. What is the concentration of a 250mL solution that contains 0.80mol of calcium chloride, CaCl 2? A. 3.2 mol/l B. 0.31 mol/l C. 0.20 mol/l D. 0.0032 mol/l 21. What volume of 0.15mol/L HCl would contain 0.30mol of HCl? A. 0.30L B. 0.50L C. 0.045L D. 2.0L 22. Which is true for diluted solution? A. The number of moles before dilution is greater than the number of moles after dilution. B. The number of moles before dilution is less than the number of moles after dilution C. The number of moles before dilution is equal to the number of moles after dilution. D. The concentration before dilution is less than the concentration after dilution. 23. Health Canada says the safe consumption limit for mercury in fish is 0.50 parts per million. What mass of mercury would be in a 325g salmon fillet which is at the legal limit for mercury? A. 1.63 x 10-4 g B. 1.63 x 10-7 g C. 6.15 x 10 3 g D. 6.15 x 10 6 g 3+ 24. What is the concentration of Al (aq) ions in a 4.00mol/L solution of Al 2(CO 3) 3 (aq)? A. 2.00mol/L B. 4.00mol/L C. 8.00mol/L D. 12.0mol/L 25. Which is NOT part of the accepted procedure for diluting a concentrated solution? A. measuring a calculated mass of reagent on a balance B. transferring the reagent into a volumetric flask C. pipetting the required volume of reagent D. calculating the required volume of reagent required 26. How many liters of 16mol/L hydrochloric acid, HCl(aq), are required to prepare 500.mL of 5.0mol/L hydrochloric acid? A. 1.6 L B. 0.63 L C. 6.4 L D. 0.16 L 27. A truck goes off the road right in front of O'Donel. The back of the truck has the label shown in Figure 1 on it. What is being transported in the truck? A. flammable materials B. oxidizing materials C. highly toxic materials D. biohazardous materials 28. What is a MSDS? A. A lab sheet which uses symbols to describe safety procedures. B. A lab sheet which describes a safety map of the lab. C. A lab sheet which outlines safety precautions for a certain substance. D. A lab sheet which explains how to dispose of a certain substance. Figure 1. Seen on a truck outside O'Donel
Page 4 of 8 29. Which apparatus is most accurate in measuring the volume of a solution? A. filter funnel B. graduated cylinder C. pipette D. beaker 30. What is the correct placement of the meniscus when using a volumetric flask? A. The bottom of the meniscus is to sit on the etched line of the flask. B. The top of the meniscus is to just touch the etched line of the flask. C. The meniscus is to be split in half by the etched line of the flask. D. The meniscus is to be just below but not touching the etched line of the flask. 31. In a mole ratio setup, what goes on the top of the ratio? A. the balancing number of the "want" chemical B. the balancing number of the "given" chemical A. the mass of the "want" chemical B. the mass of the "given" chemical 32. Given the balanced chemical equation: N 2(g) + 3 H 2 (g) 2NH 3(g) How may moles of hydrogen will combine with 2.00mol of nitrogen? A. 2.00mol B. 6.00mol C. 1.00mol D. 4.00mol 33. For the reaction: Zn + Cu(NO 3) 2 Cu + Zn(NO 3) 2 The theoretical yield of copper metal was 3.00g. If the percent yield was 78%, what mass of copper was obtained? A. 2.34g B. 0.78g C. 2.68g D. 3.85g 34. What is the excess reactant in a chemical experiment which has more than one reactant? A. the amount of product formed when a reaction is carried out in the laboratory B. the calculated amount of product formed during a limiting reactant situation C. the reactant that has more than the minimum amount needed to react with a limiting reactant D. the reactant that determines the amount of solid precipitate which can be formed in a reaction 35. What is the term for the reactant that is completely consumed? A. excess reagent B. limiting reagent C. precipitate D. percent yield
Page 5 of 8 Section II Extended Response. (35 points; 50%) Answer ALL questions in the space provided. Show math workings for all calculations, and report all final answers with correct significant digits and units. Good luck. 36. (a) Calculate the volume of 0.80mol of xenon gas, Xe(g), at standard temperature and pressure. (b) Calculate the mass of 1.08 mol of magnesium chloride tetrahydrate, MgCl 4H O.. 2 2 (3 points) Answer, (b): (c) Calculate the number of atoms in 65g of argon gas, Ar(g), at STP. Answer, (c): (d) A 5.000g sample of the compound NF x(g) has a volume of 1.577L at STP. What is "x"? (3 points) Answer, (d):
Page 6 of 8 37. (a) Calculate the lithium bromide, LiBr(aq), concentration in a stock solution made by dissolving 4.6g of lithium bromide in 250.0mL of water. (3 points) (b) In point form, describe how you would perform this process in the lab. Use as much correct lab terminology for glassware and procedure as possible. 38. (a) Calculate the final concentration of a nitric acid solution which is prepared by diluting 25.00 ml of stock 1.60 mol/l nitric acid to a volume of 2.00L. (b) Nitric acid reacts with copper metal. Consider: Beaker A contains the diluted (final) solution described above. Beaker B contains a 0.40mol/L solution of nitric acid. Briefly explain which solution would react faster.
Page 7 of 8 39. Case Study. A headline from the CBC news website, December 29, 2003 reads: Dry Cleaning Chemicals Under Scrutiny New regulations mean some dry cleaners will charge customers more for clean shirts and other goods beginning January 1, 2004. But officials with Environment Canada say the regulations are important to safeguard the environment and peoples' health. The new rules govern the use of the molecule C2Cl 4(l), tetrachloroethylene (also known as "perc"), a synthetic solvent effective in removing grease. Dry cleaners will no longer be allowed to use perc as a spotting agent. They must upgrade equipment which will cut down on the amount of fumes escaping into the air. (a) Given that the percent composition of perc is 14.49% C and 85.51% Cl, determine the empirical formula of perc. (4 points) (b) A bottle found in a dry cleaning business in Mount Pearl is found to contain a pure compound containing C and Cl only. The percent composition of the compound is 14.49% C and 85.51% Cl; the molar mass of the compound is 331.64g/mol. State whether you believe the bottle contains perc or not. You must use calculations to prove your claim. (3 points) [END OF CASE STUDY]
Page 8 of 8 40. (a) Calcium chloride reacts with silver nitrate to produce calcium nitrate and silver chloride in the following skeleton equation: CaCl 2(aq) + AgNO 3(aq) Ca(NO 3) 2(aq) + AgCl(s) Calculate the mass of silver chloride, AgCl(s), that will be produced when 0.125L of 0.500mol/L of calcium chloride solution, CaCl (aq), is reacted with excess silver nitrate solution. (4 points) 2 (b) Silver metal may be precipitated from a solution of silver nitrate using copper metal: Cu(s) + 2 AgNO 3(aq) 2 Ag(s) + Cu(NO 3) 2 (aq) If 50.0 grams of copper metal is reacted with 60.0g of dissolved silver nitrate, determine the limiting reagent, and the theoretical yield of silver metal, Ag(s), in grams. (5 points) Answer, (b): END OF EXAM.