Principles of Chemistry I Chemistry 212 Fall Final Exam

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1 Principles of Chemistry I Chemistry 212 Fall 2014 Final Exam Version B Name MULTIPLE CHOICE (1 point each). Choose the one alternative that best completes the statement or answers the question. 1) Which states of matter are significantly compressible? A) gases only B) solids only C) liquids only D) solids and liquids E) liquids and gases 1) 2)!H for an endothermic process is while!h for an exothermic process is. A) positive, negative B) negative, positive C) zero, negative D) zero, positive E) positive, zero 2) 3) The Lewis structure of PF3 shows that the central phosphorus atom has nonbonding and bonding electron pairs. A) 3, 3 B) 2, 2 C) 1, 2 D) 1, 3 E) 3, 1 3) 4) If an electron has a principal quantum number (n) of 3 and an angular momentum quantum number (l) of 2, the subshell designation is. A) 4p B) 3d C) 4s D) 4d E) 3p 4) 1

2 5) A small amount of salt dissolved in water is an example of a. A) pure substance B) heterogeneous mixture C) solid D) homogeneous mixture E) compound 5) 6) The wavelength of light emitted from a traffic light having a frequency of 5.75 x Hz is. A) 641 nm B) 583 nm C) 522 nm D) 674 nm E) 702 nm 6) 7) Which one of the following is a metalloid? A) C B) S C) Pb D) Ge E) Br 7) 8) The ground state electron configuration of Ga is. A) 1s 2 2s 2 3s 2 3p 6 4s 2 3d 10 4p 1 B) 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 1 C) 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4d 1 D) [Ar]4s 2 3d 11 E) 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 4d 10 4p 1 9) Which of the following compounds would you expect to be ionic? A) H2O B) H2S C) SrCl2 D) SO2 E) CO2 8) 9) 10) The de Broglie wavelength of a will have the shortest wavelength when traveling at 30 cm/s. A) car B) planet C) marble D) uranium atom E) hydrogen atom 10) 2

3 11) Element X has three naturally occurring isotopes. The masses (amu) and % abundances of the isotopes are given in the table below. The average atomic mass of the element is amu. 11) Isotope Abundance Mass 38 X X X A) B) C) D) E) ) Of the following transitions in the Bohr hydrogen atom, the transition results in the emission of the lowest-energy photon. A) n = 6 n = 3 B) n = 1 n = 4 C) n = 1 n = 6 D) n = 3 n = 6 E) n = 6 n = 1 12) 13) Which pair of elements below should be the most similar in chemical properties? A) C and O B) K and Kr C) Cs and He D) B and As E) I and Br 13) 14) When solutions of strong electrolytes in water are formed, the ions are surrounded by water molecules. These interactions are described as a case of. A) saturation B) crystallization C) dehydration D) supersaturation E) hydration 14) 3

4 15) The charge on the copper ion in the salt CuO is. A) -2 B) +3 C) +1 D) +2 E) -1 15) 16) The formula weight of aluminum sulfate (Al2(SO4)3) is amu. A) B) C) D) E) ) 17) The wavelength of a photon that has an energy of J is m. A) B) C) D) E) ) 18) The molecular geometry of the PF3 molecule is, and this molecule is. A) trigonal planar, nonpolar B) trigonal pyramidal, nonpolar C) trigonal pyramidal, polar D) tetrahedral, unipolar E) trigonal planar, polar 18) 4

5 19) There are electrons, protons, and neutrons in an atom of Xe. 19) A) 132, 132, 54 B) 54, 54, 132 C) 78, 78, 132 D) 54, 54, 78 E) 78, 78, 54 20) The mass % of F in the binary compound KrF2 is. A) B) C) D) E) ) 21) What volume (ml) of a concentrated solution of magnesium chloride (9.00 M) must be diluted to 350. ml to make a 2.75 M solution of magnesium chloride? A) 107 B) 50.0 C) 45.0 D) 2.75 E) ) 5

6 22) In the Lewis symbol for a sulfur atom, there are paired and unpaired electrons. A) 2, 4 B) 5, 1 C) 0, 6 D) 4, 2 E) 2, 2 22) 23) The concentration of urea (MW = 60.0 g/mol) in a solution prepared by dissolving 16 g of urea in 39 g of H2O is molal. A) 0.11 B) 6.3 C) 0.68 D) 6.8 E) 96 23) 24) A 30.5 gram sample of glucose (C 6 H 12 O 6 ) contains atoms of carbon. A) 6.12 x B) 2.04 x C) 6.02 x D) 1.02 x E) 1.22 x ) 6

7 25) Which of the following is (are) the lowest temperature? A) The freezing point of water B) 5 C C) 30 F D) 280 K E) A and D 25) 26) Given the data in the table below,!h rxn for the reaction 26) Ca(OH)2 + 2H3AsO4 Ca(H2AsO4)2 + 2H2O is kj. Substance!Hf (kj/mol) Ca(OH) H3AsO Ca(H2AsO4) H2O A) B) C) D) E)

8 27) How many moles of gas are there in a 50.0 L container at 22.0 C and 825 torr? A) 2.29 x 10 4 B) 2.23 C) 18.4 D) E) 1.70 x ) 28) The value of!h for the reaction below is -186 kj. Calculate the heat (kj) released from the reaction of 25 g of Cl2. 28) H2 (g) + Cl2 (g) 2HCl (g) A) 66 B) 47 C) D) -186 E) 33 8

9 29) The density of NO 2 in a 4.50 L tank at torr and 25.0 C is g/l. A) 9.30 B) 1.68 C) 1.88 D) 1.64 E) ) 30) On the phase diagram shown above, segment corresponds to the conditions of temperature and pressure under which the solid and the gas of the substance are in equilibrium. A) BC B) CD C) AB D) AC E) AD 30) 9

10 SHORT ANSWER (5 points each). Write the word or phrase that best completes each statement or answers the question. 31) What is the empirical formula of a compound that contains 49.4% K, 20.3% S, and 30.3% O by mass? 31) 32) What is the maximum mass in grams of NH3 that can be produced by the reaction of 1.0 g of N2 with 3.0 g of H2 via the equation below? 32) N2 (g) + H2 (g) NH3 (g) (not balanced) 10

11 33) A sample of calcium carbonate [CaCO 3 (s)] absorbs 45.5 J of heat, upon which the temperature of the sample increases from 21.1 C to 28.5 C. If the specific heat of calcium carbonate is 0.82 J/g-K, what is the mass (in grams) of the sample? 33) 34) Calculate the molality of a 25.4% (by mass) aqueous solution of phosphoric acid (H 3 PO 4 ). 34) 11

12 35) A solution containing 20.0 g of an unknown liquid and g water has a freezing point of C. Given Kf = 1.86 C/m for water, the molar mass of the unknown liquid is g/mol. 35) 36) A solution is prepared by dissolving 23.7 g of CaCl2 in 375 g of water. The density of the resulting solution is 1.05 g/ml. The concentration of CaCl2 in this solution is molar. 36) 12

13 Answer Key Testname: 212EFF14B 1) A 2) A 3) D 4) B 5) D 6) C 7) D 8) B 9) C 10) B 11) C 12) A 13) E 14) E 15) D 16) B 17) A 18) C 19) D 20) B 21) A 22) D 23) D 24) A 25) C 26) B 27) B 28) A 29) C 30) D 31) K2SO3 32) ) ) 3.47 m 35) )

CHM 151 Practice Final Exam

CHM 151 Practice Final Exam CM 151 Practice Final Exam 1. ow many significant figures are there in the result of 5.52 divided by 3.745? (a) 1 (b) 2 (c) 3 (d) 4 (e) 5 2. ow many significant figures are there in the answer when 9.021