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Introductory Chemistry CHM 1025 Test #2 1 of 10 Section: 005 Name:__________________________ Date: March 16, 2015 [Each question is worth 4 points unless otherwise stated. Checking answer without showing the set up or reasoning, when indicated, earns no credit. Good Luck!] 1. Identify, by symbol and name, all 6 metalloids found in the first 5 periods in the periodic table. [6 pts] Period 2 5 boron B 10.81 14 Period 3 Si silicon 28.0855 32 Period germa 4 nium Period 5 Ge 33 As arsenic 72.61 74.92159 antimo ny 51 52 Sb Te 121.760 127.60 telluriu m 2. The following questions on Periodic Table are worth 2 points each: a. Element M is a metal and its phosphide has the formula M3P2. To which group of the Periodic Table does element M most likely belong? 1. (IA) 2. (IIA) 3. (IIIA) 4. (IVA) 5. (VA) b. A selenium atom differs from a selenium ion in that, the atom has: a greater number of electrons a lesser number of electrons a greater atomic number a greater atomic mass a lesser number of protons 3. Write the number and name (if any) of the group (family) to which each of the following elements belong: Cesium Group 1A; alkali metal Radium Group 2A; alkaline earth metal Radon Group 8A; noble gas Chlorine Group 7A; halogen Introductory Chemistry CHM 1025 Test #2 Section: 005 Name:__________________________ 4. Write the correct name for the following elements: a. Sn: tin b. Sb: antimony c. Se selenium d. Sr: strontium 2 of 10 Date: March 16, 2015 5. Write the correct symbol for the following elements a. Vanadium V b. Gallium Ga c. Germanium Ge d. Antimony Sb 6. Write the correct name for each of the following compound. a. Na3N sodium nitride b. NaNO3 sodium nitrate c. NaNO2 sodium nitrite 7. Which pair of atoms constitutes a pair of isotopes of the same element? a. O2 & O3 b. 1 1 c. 12 6 d. e. H & 12H C & 136 C S 4 & S8 35 17 36 Cl & 17 Cl 8. What are the formulas for sulfite and chlorate ions, respectively? a. SO4, ClO2 b. HSO4ClO4 c. SO32-, ClO3 d. SO4, ClO3 e. SO3, ClO4 10/21/2015 Introductory Chemistry CHM 1025 Test #2 Section: 005 Name:__________________________ 9. Which formula/name pair is/are INCORRECT? a. Fe2S3 iron(II) sulfide b. FeSO3 iron(III) sulfite c. Fe2(SO3)3 iron(III) sulfate d. Fe2(SO4)3 iron(III) sulfate e. FeSO4 iron(II) sulfate 3 of 10 Date: March 16, 2015 10. The following table contains the names and formulas of various molecular compounds. Choose the correct answers from the following to fill in the blanks: Name Formula V2O5 Arsenic trichloride N2O5 a. vanadium pentoxide, ArCl3, dinitrogen pentoxide b. divanadium pentoxide, AsCl3, dinitrogen pentoxide c. Vanadium(V) pentoxide, As(III)Cl3, nitrogen(III) pentoxide d. Vanadium(V) pentoxide, AsCl3, dinitrogen pentoxide e. Vanadium(II) pentoxide, As2Cl3, dinitrogen pentoxide 11. The following table contains the names and formulas of various ionic compounds. Choose the correct answers from the following to fill in the blanks: Name Formula Mercury(I) Sulfide Ca3(PO4)2 Magnesium Chloride a. HgS2, Calcium Phosphide, MgCl b. Hg2S, Tricalcium diphosphate, MgCl c. HgS, Calcium phosphate, MgCl2 d. Hg2S, Calcium phosphate, MgCl2 e. HgS, Calcium phosphite, MgCl2 12. Predict the formulas of the compounds formed between – strontium and nitrogen, and aluminum and hydrogen: a. SrN and AlH b. SrN2 and AlH2 c. Sr2N3 and Al2H3 d. Sr3N2 and Al2H3 e. Sr3N2 and AlH3 10/21/2015 Introductory Chemistry CHM 1025 Test #2 Section: 005 Name:__________________________ 13. Which of the following oxides of carbon exist? 4 of 10 Date: March 16, 2015 a. CO b. CO2 c. CO3 d. a and b only e. a, b, and c 14. How many atoms are present in 4.6 mol of carbon dioxide?[Show computation details] a. 2.8 1024 b. 2.7 1024 c. 4.6 1024 d. 5.5 1024 e. 8.3 1024 6.022 1023 molecule of CO2 3 atoms 4.6 mols of CO2 8.3 1024 atom mols of CO2 molecule of CO2 15. How many g of Cl atoms are present in 10.0 g of copper(I) chloride? [Show computation details] a. 3.6 b. 2.6 c. 2.8 d. 5.3 e. None of the above 1molCuCl 1molCl 35.453g Cl 10.0 g CuCl 3.58 gCl 63.646 35.453 g CuCl molCuCl 1molC 16. What is the mass of N in 30.0 g of the amino acid, glycine, NH2CH2CO2H? [Show computation details] a. 11.2 b. 16.1 c. 9.40 d. 3.40 e. None of the above 30 g glycine 1mole of glycine 1mol N 14.0067 g N mol N 14.0067 12.011 2 1.008 5 15.999 2 g glycine 1mole of glycine 5.6 10/21/2015 Introductory Chemistry CHM 1025 Test #2 5 of 10 Section: 005 Name:__________________________ Date: March 16, 2015 17. A grain of sand weighs 7.7x10-4g. How many formula units of silicon dioxide, SiO2 are in one grain of sand? [Show computation details] 1mol SiO2 6.022 1023 formula units SiO2 7.7 104 g SiO2 1mol SiO2 28.0855 15.999 2 SiO2 7.7 1018 formula units SiO2 18. How many ions of Mg2+ are present in 3.27 102 mol of Mg2+(aq)? [Show computation details] a. 1.84 1021 b. 1.84 1025 c. 1.97 1022 d. 1.97 1026 e. None of the above 3.27 102 mol Mg 2 6.022 1023 particles of Mg 2 ions 1.97 1022 ions 2 mol Mg 19. An organic compound gave the following elemental analysis: 60.59% C, 7.12% H. Further analysis revealed oxygen to be the only other element present. Calculate its empirical formula. [Show computation details] a. C5H7O2 b. C17H2O9 basis : 100 g C 60.59 g c. C5H7O d. C8H2O4 e. C6H10O2 1mol 5.04mol ; 5.04mol 2.50 ; 2 5 2.01mol 12.011g 1mol 7.06mol ; 7.06mol 3.50 ; 2 7 2.01mol 1.008 g 1mol O 32.29 g 2.01mol ; 2.01mol 1.00 ; 2 2 2.01mol 15.999 g Thus the formula is C 5 H 7O2 H 7.12 g 10/21/2015 Introductory Chemistry CHM 1025 Test #2 6 of 10 Section: 005 Name:__________________________ Date: March 16, 2015 20. The empirical formula of ethylene, used in ripening bananas, is CH2. Its molar mass is 28.06 g/mol. What is the molecular formula of ethylene? [Show computation details] a. CH2 empirical formula mass =12.011 1.008 2 14.03 amu per formula unit or 14.03 g unit. b. C2H4 Since the molar mass of ethylene is 2 14.03g, the molecular formula is C 2 H 4 c. C3H6 d. C2H6 e. C2H2 21. Phosphoric acid is made from reaction P4O10 with water according to the following skeletal reaction: P4O10 g H 2O l H 3 PO4( aq ) a. Write the balanced equation: [4pts] P4O10 g 6 H 2O l 4 H 3 PO4( aq ) b. Name the each of the compounds in the reaction P4O10 g tetraphosrus pentoxide [4pts] 6 H 2O l 4 H 3 PO4( aq ) water phosphoric acid 22. Magnesium forms a compound with nitrogen gas to form a solid compound. a. What is its chemical formula based on their expected ionic charges: [2pts] Mg3 N 2(s) b. Write the balanced chemical equation for the reaction showing the process of production of the compound starting with magnesium and nitrogen. [4pts] 23. 3 Mg s N 2 g Mg3 N 2(s) 10/21/2015 Introductory Chemistry CHM 1025 Test #2 7 of 10 Section: 005 Name:__________________________ Date: March 16, 2015 Given the reaction Na2S(aq) + 2 AgNO3 (aq) → Ag2 S(s) + 2 NaNO3(aq) How many grams of Ag2 S will form when 3.94 g of AgNO3 and an excess of Na2S are reacted together? [Show computation details] 3.94 g AgNO3 1molAgNO3 1molAg2 S 107.8682 2 32.07 g Ag2 S 1molAg2 S 107.8682 14.0067 15.999 3 g AgNO3l 2molAgNO3 2.87 gAg2 S 24. Combustion of aspirin (C7H6O3) with air (O2) produces carbon dioxide and water vapor. The sum of the coefficients of this balanced equation is: [Show computation details] C7 H 6O3 7O2 7CO2 3H 2O C H O 7 7 6 6 3 14 14 3 The sum of the coefficients in the above equation is 1+7+7+3=18 25. Calculate the mass of AgCl that can be prepared from 200. g of AlCl3 and sufficient AgNO3, using this equation: 3 AgNO3 + AlCl3 3 AgCl + Al(NO3)3: 200.g AlCl3 1molAlCl3 3molAgCl 107.8682 35.453 g AgCl 1molAgCl 26.98154 35.453 3 g AlCl3 1molAlCl3 645 g AgCl 10/21/2015 Introductory Chemistry CHM 1025 Test #2 Section: 005 Name:__________________________ 8 of 10 Date: March 16, 2015 Common Units and Their Equivalents Length 1 kilometer (km) 1 meter (m) 1 foot (ft) 1 inch (in) = = = = = 0.6214 mile (mi) 39.37 inches (in) 1.094 yards (yd) 30.48 centimeter (cm) 2.54 cm (Exact) 1 kilogram (kg) 1 pound (lb) 1 ounce (oz) = = = 2.204 pounds (lb) 453.59 gram (g) 28.35 gram (g) = = = = 1000 milliliters (mL) 1000 cubic centimeter (cm3) or (cc) 1.057 quarts (qt) 3.785 liters (L) = r 2 , where r is the radius Mass Volume 1 liter (L) 1 liter (L) 1 US gallon (gal) Others Area of a circle 4 3 r , where r is the radius 3 Volume of a rectangular parallelepiped = length x width x height Volume of a sphere = Fundamental Physical Constants Elementary charge Avogadro number Electron rest mass Proton rest mass Neutron rest mass Charge-to-mass ratio for electron Atomic mass unit Electron radius Gas constant Acceleration due to gravity e: 1.60217733 10-19 C NA: 6.0221367 1023 particles/mol me: 9.1093897 10-31 kg mp: 1.6726231 10-27 kg mn: 1.6749286 10-27 kg {e/me} = 1.75880 1011 C/kg amu:1.66057 10-27 kg re: 2.81792 10-15 m R: 0.082057 L·atm/K·mol (8.31451 m2 kg/s2 K mol) g: 9.80665 m/s2 10/21/2015 Introductory Chemistry CHM 1025 Test #2 9 of 10 Date: March 16, 2015 Section: 005 Name:__________________________ Periodic Table of the Elements 1 H IIA 1.0079 3 4 2.998 x 108 m/s 2 Speed of Light, c = Avagadro’s Number, N =6.022 x 1023particles/mole Rydberg Constant, RH = 2.18 x 10-18 J IIIA IVA VA VIA VIIA He 4.002602 5 6 7 8 9 10 Li Be B C N O F Ne 6.941 9.012182 10.81 12.011 14.0067 15.9994 18.998403 20.180 11 12 13 14 15 16 17 18 Na Mg 22.98977 24.305 19 20 IIIB 21 IVB 22 VB 23 VIB 24 VIIB 25 ┌── VIIIB ──┐ 26 27 28 IB IIB 29 30 Al Si P S Cl Ar 26.98154 28.0855 30.97376 32.07 35.453 39.948 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 44.95591 47.867 50.9415 51.996 54.93805 55.845 58.93320 58.6934 63.546 65.39 69.723 72.61 74.92159 78.96 79.904 83.80 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 88.90585 91.224 92.90638 95.94 (98) 101.07 102.90550 106.42 107.8682 112.41 114.818 118.71 121.760 127.60 126.90447 131.29 55 56 57 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 Cs Ba La* Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn 132.9054 137.33 138.9055 178.49 180.9479 183.84 186.207 190.23 192.217 195.08 196.96654 200.59 204.3833 207.2 208.98037 (209) (210) (222) 87 88 89 104 105 106 107 108 109 110 111 112 114 116 Fr Ra Ac (223) (226) (227) (289) (292) 70 71 † Rf Db Sg Bh Hs Mt Ds (263) (262) (266) (267) (277) (268) (281) (272) (285) 58 59 60 61 62 63 64 65 * 66 67 68 69 Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu 140.12 140.90765 144.24 (145) 150.36 151.96 157.25 158.92534 162.50 164.93032 167.26 168.93421 173.04 174.967 10/21/2015 Introductory Chemistry CHM 1025 Test #2 10 of 10 Date: March 16, 2015 Section: 005 Name:__________________________ † 90 91 92 93 94 95 96 97 98 99 100 101 102 103 Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr 232.0381 231.03588 238.0289 (237) (244) (243) (247) (247) (251) (252) (257) (258) (259) (262) 10/21/2015