1 IA 1 ydrogen 1.01 Atomic number Element symbol Element name Atomic mass VIIIA 1 1.01 IIA IIIA IVA VA VIA VIIA 2 e 4.00 Metalloids 3 Li 6.94 4 Be 9.01 5 B 10.81 6 C 12.01 7 N 14.01 8 O 16.00 9 F 19.00 10 Ne 20.18 11 Na 22.99 12 Mg 24.31 IIIB IVB VB VIB VIIB VIIIB IB IIB 13 Al 26.98 14 Si 28.09 15 P 30.97 16 S 32.07 17 Cl 35.45 18 Ar 39.95 19 K 39.10 20 Ca 40.08 21 Sc 44.96 22 Ti 47.88 23 V 50.94 24 Cr 52.00 25 Mn 54.94 26 Fe 55.85 27 Co 58.93 28 Ni 58.69 29 Cu 63.55 30 Zn 65.39 31 Ga 69.72 32 Ge 72.59 33 As 74.92 34 Se 78.96 35 Br 79.90 36 Kr 83.80 37 Rb 85.47 38 Sr 87.62 39 Y 88.91 40 Zr 91.22 41 Nb 92.91 42 Mo 95.94 43 Tc (99) 44 Ru 101.07 45 Rh 102.91 46 Pd 106.42 47 Ag 107.87 48 Cd 112.41 49 In 114.82 50 Sn 118.71 51 Sb 121.75 52 Te 127.60 53 I 126.90 54 Xe 131.29 55 Cs 132.91 56 Ba 137.33 57 La 138.91 72 f 178.49 73 Ta 180.95 74 W 183.85 75 Re 186.91 76 Os 190.23 77 Ir 192.22 78 Pt 195.08 79 Au 196.97 80 g 200.59 81 Tl 204.38 82 Pb 207.2 83 Bi 208.98 84 Po (209) 85 At (210) 86 Rn (222) 87 Fr (223) 88 Ra (226) 89 Ac (227) 104 Rf (261) 105 Db (262) 106 Sg (263) 107 Bh (262) 108 s (265) 109 Mt (266) Lanthanide series 58 Ce 140.12 59 Pr 140.91 60 Nd 144.24 61 Pm (147) 62 Sm 150.36 63 Eu 151.97 64 Gd 157.25 65 Tb 158.93 66 Dy 162.50 67 o 164.93 68 Er 167.26 69 Tm 168.93 70 Yb 173.04 71 Lu 174.97 Actinide series 90 Th (232) 91 Pa (231) 92 U (238) 93 Np (237) 94 Pu (244) 95 Am (243) 96 Cm (243) 97 Bk (247) 98 Cf (251) 99 Es (252) 100 Fm (257) 101 Md (258) 102 No (259) 103 Lr (260) Feel free tear off this page from the rest of exam
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Spring 2016 Chem3 Test 3 Name MULTIPLE COICE. 3 pts for each choice. 1) The total number of valence electrons in NO2 + is A) 18 B) 23 C) 17 D) 16 Score /150 1) 2) Which of the following Lewis structures does NOT fulfill the octet rule? A) : C ::: P : B) : C : : S : 2) C) : O : C : O : D) : C : N : 3) ow many VSEPR electron groups are on the central atom in the Lewis structure : A) 4 B) 1 C) 2 D) 3 F : N :: O 3) 4) The molecule AXY with three VSEPR electron groups on the central atom A would look like which one of the following 4) A) B) C) D) none of the above 5) The molecular geometry of the molecule with a Lewis structure as : A) tetrahedral B) linear C) trigonal pyramidal D) trigonal planar F : C :: O 5) 6) The molecular geometry of the molecule with a Lewis structure as : P : F : 6) A) tetrahedral B) bent C) trigonal pyramidal D) trigonal planar A 1
7) Using VSEPR theory, predict which of the following triatomic molecules has bond angle of 109.5 A) : Cl : O : F : B) : O : : N : C) : O : : C : : O: D) : Cl : 8) Which of the following molecules is polar? A) C4 B) CO2 C) I2 D) SO2 9) Which one of the following hypothetical molecules is NOT polar? (A as central atom) A) Tetrahedral AXY3 B) Linear AXY N :: O : 7) 8) 9) C) Bent X-A-X D) Trigonal Planar AX3 10) What is the molar mass of KClO3? 10) A) 122.55 g B) 90.55 g C) 161.45 g D) 6.02 1023 g 11) ow many moles of oxygen are in 2.0 mol Ca(ClO3)2? A) 3.0 mol B) 12.0 mol C) 2.0 mol D) 6.0 mol 11) 12) 2.00 mol water weighs grams. A) 18.0 B) 2.00 C) 36.0 D) 34.0 12) 13) What is the empirical formula of a compound that consists of 0.012 mol carbon, 0.024 mol, and 0.012 mol oxygen? A) CO B) CO2 C) C2O D) C2O 13) 14) Alka-Seltzer tablets fizzles when dissolved in water C68O7 + 3 NaCO3 Na3C65O7 + 3 CO2 + 3 2O Based on this equation, how many moles of C68O7 is needed to react with 1.8 mol NaCO3? A) 3.6 mole B) 1.8 moles C) 5.4 mole D) 0.60 mole 14) 15) A car tire is filled with air at 2.40 atm and has a volume of 30.0 L. When the tire hit the curb, its volume becomes 28.0 L at the same temperature, the pressure will become A) 2.40 atm B) 2.25 atm C) 2.57 atm D) none of the above 15) 16) STP (standard temperature pressure) refers to A) 1 atm, 25 C B) 1 atm, 273 K C) 1 atm, 0 F D) 1 atm, 298 K 16) 17) The density of hydrogen gas at STP (in g/l) is A) 0.0450 B) 2.00 C) 1.00 D) 0.0900 17) TRUE/FALSE. Write T if the statement is true and F if the statement is false. 2 pts for each question. 18) According to the gas laws, for the same amount of gas at the same pressure, the volume of the gas would decrease as the temperature of the gas increases. 18) 19) At the same volume, the pressure of the gas would decrease as the temperature of the gas increase. 19) A 2
PROBLEMS. Show work with proper Significant Figures and Units to receive credit. 10 pts for each question unless otherwise noted. 20) (8 pts) ow many moles of Pb(NO3)2 are in 1.00 g Pb(NO3)2? 21) (12 pts) Draw Lewis structures AND find the bond angles for the following : NO2 - NO Bond angle: <O-N-O = <-N-O =. 22) In a hot summer afternoon, a helium balloon had a volume of 20.0 L at a pressure of 1.50 atm at 34 C. By early morning, the temperature becomes 6 C and volume drops to 19.0 L. Calculate the pressure of the balloon in the early moring. 23) (12 pts) Draw Lewis structures AND find the bond angles for the following : C3F ClCN Bond angle: <-C-F = <Cl-C-N =. A 3
24) (16 pts + 6 pts) An unknown organic compound has a composition of 39.12% C,8.76%, and 52.12% O. a. Calculate the empirical formula of glycerin without using its molar mass. b. This compound has a molar mass of 184.2 g/mol. Determine the molecular formula of the compound. 25) (16 + 10 + 3 pts) ydroben gas can be made from reaction between aluminum and hydrochloric acid: 6Cl + 2Al 2AlCl3 + 32 a. If 1.50 g Al is mixed with 15.0 g Cl, calculate the theoretical yield of hydrogen gas (in grams) in this reaction. A 4
b. Calculate the pressure (in atm) if all the hydrogen gas from part a is collected in a 1.50 L bottle at 12 C. c. If the actual yield of hydrogen gas is 0.10 g, what is the percent yield of hydrogen gas in this reaction? A 5