fl HHmIBIH UNIVERSITY OF SCIENCE nnd TECHNOLOGY FACULTY OF HEALTH AND APPLIED SCIENCES DEPARTMENT OF NATURAL AND APPLIED SCIENCES QUALIFICATION: BACHELOR OF SCIENCE QUALIFICATION CODE: O7BOSC LEVEL: 5 COURSE CODE: GNCSOIS COURSE NAME: GENERAL CHEMISTRY 1A SESSION: JULY 2017 PAPER: THEORY DURATION: 3 HOURS MARKS: 100 EXAMINER(S) SUPPLEMENTARY/SECOND OPPORTUNITY EXAMINATION QUESTION PAPER DR. EUODIA HESS MODERATOR: DR. MARIUS MUTORWA PEUN! INSTRUCTIONS Answer ALL the questions. Write clearly and neatly. Number the answers clearly All written work must be done in blue or black ink and sketches can be done in pencil 5. No books, notes and other additional aids are allowed THIS QUESTION PAPER CONSISTS OF 11 PAGES (Including this front page, list of constants and periodic table)
SECTION A [60] QUESTION 1: Multiple Choice Questions [60] There are 20 multiple choice questions in this section. Each question carries 3 marks. Answer ALL questions by selecting the letter of the correct answer. Choose the best possible answer for each question, even if you think there is another possible answer that is not given. Convert 12300 to scientific notation. 1,2300 1.2300 1.2300 x 104 1.23 x 104 Insufficient information An object has a volume of 0.0010 m3. Its volume given in cm3 is A. B C. 0.10 1000 100 D.10 E 1 Which of the following classifications of elements is NOT correct (is FALSE)? A. Sn (Z = 50) is a transition metal Ba (Z = 56) is an alkaline earth metal 01.0.0.0 As (2 = 33) is a metalloid I (Z = 53) is a halogen Kr (Z = 36) is a non-metal Which one of the following Name-Formula combinations is NOT correct (is FALSE)? A. B. C D. E Mercury (I) chloride, HgZClz Dinitrogen trioxide, N203 Hydrogen chloride, HCI Cerium (IV) phosphate, Ce4(PO4)3 Silver (ll) fluoride dihydrate, Ang'ZHZO Page 2 of 11
. The. Which For a particular organic compound, which of the following pairs can represent the empirical and the molecular formulas, respectively? A. CH and CH4 B. CH and C5H6 C. CH2 and CZHZ D. CH2 and C2H3 E. CH3 and C3H5 percent manganese in potassium manganate, KzMnO4, is: A. 13.2% B 22.6% C. 29.0% D. 34.8% E 27.9% one of the following sets of quantum numbers, {n, l, m,, m5}, describing the indicated orbital, is NOT CORRECT (is not possible)? an electron in A. {1, 0, 0, 1/2}, 15 W909? {5, 2, 2, 1/2}, 5p {3, 2, -1, 1/2}, 3d {3, 1, 1, 1/2}, 3p {4, o, 0, 1/2}, 45 In the ground state electronic configuration of 33As, how many electrons have /= 1 as one of their 4 quantum numbers? A. 3 B. 9 C 12 D. 15 E 18 Page 3 of 11
9. In the equation Al(OH)3 + H2504 9 A 2(SO4)3 + H20, the coefficients of the balanced equation are: 1, 3, 1, 2 { 90ij 2, 3, 2, 6 2, 3, 1, 6 2, 6, 1, 3 1, 3, 1, 6 10. If 10 ml of 1 M HCI was required to titrate a 20 ml of NaOH solution of unknown concentration to its endpoint, what was the concentration of the NaOH? A. 0.5 M 1 M meow 1.5 M 2 M 2.5 M 11. Which ine(s) show the relationship of gas volume to pressure with temperature and amount of gas held constant? A. Ionly B. H only C. III only D. IV only E. II and IV Page 4 of 11
12. A 5.00 g sample of nitrogen gas (N2) is contained in a 800 ml flask. If the temperature is -15 C, what is the pressure of the gas if it behaves as an ideal gas? A. 6.05 atm B. 4.74 atm C 5.64 atm D. 5.30 atm E 3.75 atm 13. Standard conditions (STP) are: A. 0 C and 2 atm 32 F and 76 torr W90? 273 K and 760 mmhg 4 C and 7.6 cmhg 0 K and 760 mmhg 14. What is the concentration of the solution prepared by diluting 0.200 L of a 2.00 M solution to a final volume of 0.800 L? A. 8.00 M B. 0.200 M C. 0.500 M D. 0.400 M E 0.800 M 15. At STP, two moles of any ideal gas occupy: A. 20.4 L 22.4 L F0909 44.8 2.04 L 2.24 L L Page 5 of 11
16. A gas is most soluble in a liquid at A. low temperature and low pressure B. high temperature and high pressure high temperature and low pressure.0 low temperature and high pressure 1' None of the above 17. State the van't Hoff factor (i) for a dilute aqueous solution of the strong electrolyte barium hydroxide, Ba(OH)2. A.O.moow thi x 18. In general, colloidal particles remain dispersed because of their size WPOFD? their mass their rapid motion their electric charge the reduction in viscosity continuous phase 19. What is the name of the following hydrocarbon according to the IUPAC rules? 3,3-dimethyI-S propylhexane FPO??? 6,6-dimethyl 4 propyloctane 3,3-diethyl-5 propyloctane 5,5-dimethyl 3 butyloctane 3,3-dimethyI S-propyloctane Page 6 of 11
20. Which ofthe following alkanes would have the highest boiling point? (a) CH3- CH2 CH2- CH2- CH2- CH2- CH3 (b) (EH3 [CH3 CH3- C- CH CH3 CH3 (C) (d) CH3- CH2- CH2- CH2- CH CH3 CH3- CH CHg- CH CH3 CH3 CH3 CH3 A. (a) B. (b) C. (c) D. (cl) E. (a) and (c) Page 7 of 11
SECTION B [40] There are SEVEN questions in this section. Answer all Questions. Show clearly, where necessary, how you arrive at the answer as the working will carry marks too. Question 1 [4] For each of the following, give the corresponding name or formula (a) Copper (II) sulphate pentahydrate (1) (b) Dichlorine heptoxide (1) (c) C03(PO4)2'6H20 (1) (d) P456 (1) Question 2 [7] Cadaverine, a foul smelling substance produced by action of bacteria on meat, contains 58.55% carbon, 13.81% hydrogen, and 27.40% nitrogen by mass and has a molar mass of 102.2 g/mol. Determine: (a) empirical formula, and; (5) (b) molecular formula of the substance. (2) Question 3 [9] A student synthesised 1.50 g aspirin (C9H304) in a laboratory by reacting 1.50 g salicylic acid (C7H503) with 2.00 g acetic anhydride (C4H503). The balanced equation is C7H503 + C4H503 9 C9H304 + HC2H302 Molar masses (g/mol): C7H503= 138.12; C4H503 = 102.09; C9H804 = 180.16 (a) Which compound is the limiting reactant? (3) (b) What is the theoretical yield of aspirin? (2) (c) How much of excess reactant in grams remains after the reaction is completed? (2) (d) What is the percentage yield? (2) Page 8 of 11
Question 4 [3] A scuba diver s tank contains a certain amount of 02 compressed into a volume of 2.3 L, pressure of 91 atm and temperature inside the tank of 9 C. What volume would this oxygen occupy at 26 C and 0.95 atm? Question 5 [9] An aqueous solution that contains 571.6 g sulphuric acid (H2504) in one liter of solution has a density of 1.329 gcm'3. Calculate the following for the H2504: (a) Molarity (2) (b) Mass percent (3) (c) Molality (2) (d) Mole fraction (2) Question 6 [8] (a) Write the lupac names of the following compounds: (2) (i) (ii) (b) State the functional group in each of the following compounds: (6) Page 9 of 11
O (H) (iii) CH3 C OH fi CH3 C - OCH3 (iv) CHg NH CHz CHg (V) M) CH3 OH E CH3 C <:H3 THE END GOODLUCK USEFUL CONSTANTS: Gas constant, R = 8.3145 J 'mol'l' K'1 = 0.083145 dm3'bar'mol'1'k'1= 0.08206 L atm mol'l' K'1 lpa'm3=1kpa.l =1N'm :11 1 atm = 101 325 Pa = 760 mmhg = 760 torr Avogadro s Number, NA = 6.022 x 1023 mol 1 Planck s constant, h = 6.626 x 10'34 J5 Speed of light, c = 2.998 x 108 ms'1 Page 10 of 11
PERIODIC TABLE OF THE ELEMENTS l 18 l 2 H He 1.00794 2 13 4 15 16 '7 4.00260 Page 11 of 11 3 4 5 6 7 8 9 10 Li Be B C N 0 F Ne 6.941 9.01218 10.81 12.011 14006715999418.9984 20.179 11 12 13 14 15 16 17 18 Na Mg AI Si P S Cl Ar 22.9898 24.305 3 4 5 6 7 8 9 10 11 12 26.9815 28.0855 30.9738 32.06 35.453 39.948 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 K Ca Sc Ti V Cr Mn Fe Co. Ni Cu Zn Ga Ge As Se Br Kr 39.0983 40.08 44.9559 47.88 50.9415 51.996 54.9380 55.847 58.9332 58.69 63.546 6538 69.72 72.59 74.9216 78.96 79.904 83.8 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe 85.4678 87.62 88.9059 91.22 92.9064 95.94 (98) 101.07 102.906 106.42 107.868 112.41 114.82 118.69 121.75 127.6 126.9 13129 55 56 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 C8 Ba Lu Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn 132.905 137.33 174.967 178.49 180.948 183.85 186207 190.2 192.22 195.08 196.967 200.59 204.383 2072 208.908 (209) (210) (222) 87 88 103 104 105 106 107 108 109 110 111 112 114 116 118 Fr Ra Lr Rf Db Sg Bh HS Mt Uun Uuu Uub Uuq Uuh Uuo (223) 226.025 (260) (261) (262) (263) (264) (265) (268) (269) (272) (269) Lanthflnidfi: S7 58 59 60 61 62 63 64 65 66 67 68 69 70 La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb 138.906 140.12 140.908 14424 (145) 15036 151.96 15725158925 162.50 161.930 167.26 166.934 173.04 Actinides: 89 90 91 92 93 94 95 96 97 98 99 100 101 102 Ac Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No 227.028 232.038 231.036 238.029 237.048 (244) (243) (247) (247) (251) (252) (257) (258) (259)