CHM 2045C Exam 2 Fall 2023 PDF

Key B Name: _____________________________________ CHM 2045C Exam II Fall 2023 B For the following questions (1-15) choose the correct answer and place it in the space to the left of the question number. (2 points each) _____ 1. How many pi bonds are there in HSO3-1?...

Key B Name: _____________________________________ CHM 2045C Exam II Fall 2023 B For the following questions (1-15) choose the correct answer and place it in the space to the left of the question number. (2 points each) _____ 1. How many pi bonds are there in HSO3-1? a. 4 b. 3 c. 2 d. 41 _____ 2. Sodium Chloride is 39% sodium by mass. Which of the following is true? a. A teaspoon of salt only contains Na+ b. In a 100 g sample 61 g is chloride c. Table salt contains chlorine gas. d. Sodium chloride is explosive. _____ 3. sp3 hybridization is usually associated with which of the following electron pair geometries? a. Tetrahedral b. Octahedral c. Linear d. Trigonal planar _____ 4. A bond that results from a positive ion bound to a negative ion is a(n) a. Ionic Bond b. Metallic Bond c. Covalent Bond d. None of the above _____ 5. What is the empirical mass for Ribose C5H10O5? a. 180.156 g/mole b. 60.06 g/mole c. 120.12 g/mole d. 30.03 g/mole _____ 6. Which of the following theories explains how carbon can bond to four hydrogens in CH4? a. Hybridization b. Lewis c. VSEPR d. Molecular Orbital _____ 7. Most of the compounds exhibiting covalent bonds are usually between: a. A metal and a non-metal. b. Two non-metals. c. Two metals d. None of the above _____ 8. Which of the following shows an exception to the octet rule? a. Boron b. Fluorine c. Oxygen d. Carbon B _____ 9. When the enthalpy of a reaction is positive then the enthalpy change is said to be a. Exergonic b. Exothermic c. Endothermic d. None of the above _____ 10. If the difference in electronegativity between two nuclei is between 0.1 and 0.4 then the bond is said to be a. pure covalent b. Polar covalent c. Ionic d. Nonpolar covalent e. None of the above _____ 11. What is the molecular geometry for BrF5? a. Square Pyramid b. Tetrahedral c. Octahedral d. See-Saw e. Square Pyramid f. None of the above _____ 12. Which of the following is soluble in methanol CH3OH? a. Hexane, C6H14 b. Water c. Mineral Oil d. CCl4 _____ 13. Which of the following does not have to go to the excited state before hybridizing? a. NH3 b. CCl4 c. BF3 d. XeF4 _____ 14. Which of the following is Paramagnetic? a. B2 b. H2 c. C2 d. N2 _____ 15. Which of the following theories best explains oxygen? a. Lewis b. VSEPR c. Molecular Orbital d. Hybridization B Part B Completion: For each of the following give the requested information, please show the information clearly. This section is worth a total of 38 points. 1. (3 points) For each of the following, give the name of the compound. Tin(#) Phosphate a. Sn3(PO4)4 ____________________________________ trinitrogen hexafluoride b. N3F6 _________________________________________ Iron (1) Chlorite c. Fe(ClO2)2 _______________________________________ 2. (3 points) For each of the following, give the formula for the compound. P3 Brs a. triphosphorouspentabromide ______________________________ Tiz (PO3)2 b. Titanium (II) phosphite ______________________________ Hy50y (ag) c. Sulfurous acid ________________________________ 3. (6 points) Draw a molecular orbital diagram for OF -, determine the bond order, and then answer the questions in the box. Bond order: ____________________ Yes Can it exist:____________________ What type of bond would exist between the atoms: ______________ single Magnetic nature:____________________ Diamagnetic 41 4111 1141 11 If Y Ch If 4 bond order= =1 B 1. (6 points) Explain why C2F2H2 can be non-polar or polar. 2. (10 points) For each of the following molecules: draw the Lewis dot structure include any formal charges that may be present, give the name of the shape, state whether the molecule is polar or non-polar and give the hybridization of the central atom. Formula Lewis dot structure Molecular Shape Polar/ Non- Hybridization of (Charge minimized) Name polar the Central Atom SO3- PCl5 B 4. (4 points) (a)Show the Lewis dot structure for SbO4-3 in a charge minimized state (b)show the formal charge on each atom and (c) give the overall charge on each of the oxygens. 5. (6 pts) Using diagrams and words explain how the Antimony in SbO4-3 would undergoes hybridization. (make sure to show and minimize any formal charges and give the complete hybridization process)  B Part C Problems: For each of the following problems: show your work, remember sig. figs., and units. When you get your final answer place your answer in the box. This section is worth 32 points. 1. (8 pts) For the following reaction calculate the Enthalpy of reaction in kJ/mole and state if the reaction is endothermic or exothermic? - 2 - - I C - H6 414 C - H 6 414 c - C 3347 C C 347 C-214339 - C = C 2 611 Cl - C 2 243 347) + (4 339) - (3. 4147 + 347) + (2 611) + (2 243)] [16. 14) +(1 - [(6 4 -. Hmxn. · = -HrXn = 4539 - 4881 Haxn=- 342 mole 2. (6 pts) Determine the percent composition of each element in Calcium Sulfate. CaSOy 200 % =29 % glmle % Ca =. 44 136 15. % 5 = 32. 07 x 100 % = 23. 55 % 136 15. %= 47 % 100x100 0 %0. = %S = 23 55 %. %Ca = 29 44 %. %O= 47. 01 % B 3. (8 pts) Determine the number of moles of dinitrogen pentafluoride found in a perfect cube of dinitrogen pentafluoride measuring 2.15 cm on it side. (the density of dinitrogen pentafluoride is 2.75 g/cm3) (Hint: Volume of a cube is (side) 3). 4. (10 points) Determine the empirical formula and the molecular formula for a compound that has a sample size of 7.862 g. When the sample undergoes combustion analysis 5.99650 g of water and 14.64516 g carbon dioxide are formed. The molar mass of the compound is 236.26 g/mole. Empirical Formula = Molecular Formula = Total - _____ / 100 B Average Bond Energies B