Exam 2 Form C Key 1 E 2 D 3 E 4 A 5 D 6 E 7 D 8 C 9 D 10 E 11 B 12 E 13 A 14 B 15 B 16 C 17 C 18 C 19 A 20 E 21 C 22 A 23 SP 1 2 32 26 3 a b F As SP 1 2 32 24 4 F F c no yes d 1 1 33 e 3 3 f 0 1 g 109o 120o h trigonal pyramidal trigonal planar i sp3 sp2 O B O O For the next two questions consider the following samples A 3 mol of LiH B 1 mol of SiH4 C 3 x 1023 Cl2 molecules 23 E 6 x 10 HF molecules D 2 mol F2 1 Which sample contains the least mass 2 Which sample contains the greatest mass 3 Consider the following three structures and select the accurate statement Note there is a negative formal charge shown on structure 3 O H H C H H C O H H H O C C O 3 2 H H A Structure 1 has the shortest CO bond and structure 3 has the strongest CO bond B Structure 3 has the longest CO bond and structure 1 has the weakest CO bond C Structure 2 has the shortest CO bond and structure 3 has the strongest CO bond D Structure 1 has the longest CO bond and structure 2 has the weakest CO bond E Structure 2 has the longest CO bond and structure 1 has the strongest CO bond 1 4 What can you say about the polarity of H2O CH4 and CO2 A H2O is polar whereas CH4 and CO2 are not B H2O and CH4 are polar whereas CO2 is not C H2O CH4 and CO2 are all polar D CO2 is polar whereas H2O and CH4 are not E CO2 and CH4 are polar whereas H2O is not 5 Select the material with the lowest boiling point A Cl2 B HCl C H2S D N2 E NH3 6 Assuming other factors stayed constant an increase in the temperature of a gas is consistent with A A decrease in the pressure of the gas B A decrease in the volume of the gas C An increase in the number of moles of the gas D All of these E None of these 7 Materials with high boiling points will also have A weak intermolecular forces and high vapor pressures B weak intermolecular forces and low vapor pressures C strong intermolecular forces and high vapor pressures D strong intermolecular forces and low vapor pressures 8 Select the correct statement A In a sigma antibonding interaction most of the electron density is between the nuclei along the internuclear axis B In a sigma bonding interaction there is very little electron density between the nuclei C In a pi antibonding interaction there is very little electron density between the nuclei D In a pi bonding interaction most of the electron density is between the nuclei along the internuclear axis 9 In drawing Lewis structures as we will do on the last page of this exam we follow the octet rule BUT if you were asked to critique the following two structures of SO2Cl2 neither of which follow the octet rule which would you say is better and why lone pairs not shown O 1 Cl S 2 Cl O O S O Cl Cl A Structure 1 is better because the O and Cl atoms have formal charges B Structure 1 is better because there are no formal charges on the O or Cl atoms C Structure 2 is better because the O and Cl atoms have formal charges D Structure 2 is better because there are no formal charges on the O or Cl atoms 10 Which of the following represents a sigma antibonding interaction A B C D E 11 Comparing CO2 gas and Cl2 gas both at room temperature you would conclude A They have the same average kinetic energies and speeds B They have the same average kinetic energy but CO2 has the greater speed C They have the same average kinetic energy but Cl2 has the greater speed D They have the same speed but CO2 has the greater average kinetic energy E They have the same speed but Cl2 has the greater average kinetic energy For the next two questions consider the following samples A 2 mol of H2Se B 1 mol of H2SO4 C 2 mol of PCl3 D 3 mol of SO2 E 0 5 mol of C5H10O5 12 Which sample contains the greatest number of total atoms 13 Which sample contains the least number of total atoms For the next nine questions consider this molecule Note All atoms obey the octet rule Lone pairs have not been shown but must be considered when answering these questions H H O H H Cl C C H O C C C C 1 2 3 C N C C H 4 14 What are the bond angles at carbon 8 A 90o B 109o C 120o 15 What is the hybridization at carbon 2 C sp3 A sp B sp2 C H H 5 6 7 C N Cl H 8 H 9 D 180o D sp4 16 What is the shape at carbon 3 A linear B bent C trigonal planar D trigonal pyramidal 17 What is the bond angle at nitrogen 6 A 90o B 109o C 120o D 180o 18 What is the hybridization at nitrogen 9 A sp B sp2 C sp3 D sp4 19 What is the shape at carbon 7 A linear B bent C trigonal planar 20 How many pi bonds exist in this molecule A 3 B 4 C 5 C D 6 D trigonal pyramidal E 7 21 What is the bond order of the bond between carbon 3 and carbon 4 A 1 B 1 33 C 1 5 D 2 E 3 22 What is the bond order of the bond between carbon 8 and nitrogen 9 A 1 B 1 33 C 1 5 D 2 E 3 E tetrahedral E tetrahedral 23 Answer the following questions for AsF3 and BO33 where all atoms obey the octet rule a 10 each Draw the Lewis structure for each species if resonance structures exist only draw one AsF3 BO33 b 4 each If you haven t done so already add formal charges to your structure The remaining parts of this question will be graded on the structures you have drawn above c 2 each Yes or no do other resonance structures exist for AsF3 BO33 d 2 each Based on your structure what is the As F bond order in AsF3 BO bond order in BO33 BO33 e 2 each How many sigma bonds are in AsF3 BO33 f 2 each How many pi bonds are in AsF3 BO33 g 4 each What is are the bond angle s in AsF3 h 4 each Based on your structure what is the shape of AsF3 BO33 i 4 each Based on your structure what is the hybridization …