(Z = 53) is a halogen. Hydrogen chloride, HCI. Mercury (I) chloride, HgZClz. Dinitrogen trioxide, N203 1,2300

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1 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)

2 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 to scientific notation. 1, x x 104 Insufficient information An object has a volume of m3. Its volume given in cm3 is A. B C 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 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

3 . 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

4 9. In the equation Al(OH)3 + H 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, 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

5 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 atm B atm C 5.64 atm D 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 L of a 2.00 M solution to a final volume of L? A M B M C M D M E M 15. At STP, two moles of any ideal gas occupy: A L 22.4 L F L 2.24 L L Page 5 of 11

6 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

7 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

8 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 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= ; C4H503 = ; C9H804 = (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

9 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 g sulphuric acid (H2504) in one liter of solution has a density of 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

10 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 = J 'mol'l' K'1 = dm3'bar'mol'1'k'1= L atm mol'l' K'1 lpa'm3=1kpa.l =1N'm :11 1 atm = Pa = 760 mmhg = 760 torr Avogadro s Number, NA = x 1023 mol 1 Planck s constant, h = x 10'34 J5 Speed of light, c = x 108 ms'1 Page 10 of 11

11 PERIODIC TABLE OF THE ELEMENTS l 18 l 2 H He ' Page 11 of Li Be B C N 0 F Ne Na Mg AI Si P S Cl Ar K Ca Sc Ti V Cr Mn Fe Co. Ni Cu Zn Ga Ge As Se Br Kr Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe (98) C8 Ba Lu Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn (209) (210) (222) Fr Ra Lr Rf Db Sg Bh HS Mt Uun Uuu Uub Uuq Uuh Uuo (223) (260) (261) (262) (263) (264) (265) (268) (269) (272) (269) Lanthflnidfi: S La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb (145) Actinides: Ac Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No (244) (243) (247) (247) (251) (252) (257) (258) (259)