Chemistry 110 Name Practice Exam 2A Section Midterm 1 Signature IMPORTANT On the scantron answer sheet you MUST clearly fill your name your student number section number and test form white cover test form A yellow cover test form B Use a 2 pencil There are 28 questions on this exam Check that you have done all of the problems and filled in the first 28 bubbles on the scantron The maximum score on this exam is 28 points Your score will be reported in percents max 100 Exam policy This cover sheet must be signed and handed in with your answer sheet for your exam to count Calculators with text programmable memory are not allowed Relevant data and formulas including the periodic table are attached at the end of this exam Your grade will be based only on what is on the scantron form The answer key will be posted on the web after the exam under Exam Schedule Hints As you read the question underline or circle key words to highlight them for yourself Avoid errors from mis reading the question Pay attention to units and magnitudes decimal places of numbers obtained from calculations There is no penalty for guessing CHEMISTRY 110 PRACTICE EXAM 2A 1 What is the total number of valence electrons present in PO43 A 24 B 27 C 30 D 32 E 33 2 Which of the following is an incorrect Lewis structure for the most stable state of the molecule or ion shown A C O B O S C E C Cl N O O D C Cl C H O H 3 Draw Lewis structures for NO2 NO2 and NO3 Based on the interpretation of the Lewis structures put these in order of increasing bond order A NO2 NO2 NO3 B NO2 NO3 NO2 C NO2 NO3 NO2 D NO3 NO2 NO2 E NO2 NO2 NO3 4 Which of the following best describes propane butane and octane A The molecules contain only C O and H B The molecules contain only C and H and are isomers of each other C The molecules contain only C and H and at least 1 double bond D The molecules contain only C and H and only single bonds E The molecules share no common characteristics 5 Which of the following best describes the electron domain geometry of bromine pentafluoride A trigonal bipyramidal B seesaw shaped C tetrahedral D square pyramidal E octahedral 6 Put these in order of increasing electronegativity Ca Si O Al Ba A Ba Ca Al Si O B Ca Ba Si Al O C O Al Si Ca Ba D Al Ca Ba Si O E Ba Ca O Al Si 7 What is the empirical formula for the compound drawn below O A C3H4O O B C9H12O3 C C8H9O3 H O D CHO E C9H11O3 8 Which of the following molecules possesses the most number of equivalent resonance structures A SO32 B NO2 C CH4 D CO2 E SO2 9 Which of the following is correct regarding structural isomers i They have different molecular formulas ii They have the same connectivity of the atoms iii They have the same molar mass A i only B ii only C iii only D i and iii E all of these are true 10 An unknown compound is analyzed and found to contain C H and Br Upon further analysis it is also found to be 45 9 carbon and 3 21 hydrogen Which of the following could be the unknown compound 11 Which of the followings pairs are isomers A II only I B II and III only C I II and IV only D I II III and IV only OH II OH E II III and IV only III Cl Cl IV 12 Which one of the following molecules does NOT have a geometric isomer 13 Which functional group is NOT present in the compound shown below A amide B carboxylic acid C ester D amine E alcohol 14 Which of the following molecules will adopt a trigonal planar geometry I II III BF3 ClF3 NH3 A I only B II only C III only D I and II only E I II and III 15 Which orbital hybridization s of the C atoms is are exhibited in the molecule shown below i ii iii sp sp2 sp3 A i and ii only B ii and iii only C i and iii only D iii only E all three are exhibited 16 Which figure best illustrates the hybridization of the central sulfur atom in sulfur dioxide SO2 and the central carbon atom in carbon disulfide CS2 i ii SO2 CS2 A iii i B ii ii C i iii D ii i iii E i i 17 Which of the following choices gives the correct number of and bonds in the molecule shown A 14 5 B 15 5 C 15 6 D 20 6 E 25 6 18 Which of the following molecules is nonpolar A ICl3 B NF3 C BrF3 D PCl3 E BF3 19 Which of these molecules has a stable structure that violates the octet rule i ii iii BH3 NO XeF2 A ii only B iii only C i and ii only D i and iii only E All three have a stable structure that violates the octet rule 20 Use your knowledge of VSEPR theory to rank the indicated bond angles in order of decreasing angle I O OH C H O H C CH2 II III H A II I III B I II III C II III I D III II I E I III II 21 When covalent bonds are broken energy is A released B consumed C sometimes consumed sometimes released D destroyed E converted to nuclear power 22 A compound containing only P Cl bonds was analyzed and found to contain by mass 22 6 phosphorus What is the hybridization of the phosphorus atom A sp3d2 B sp3d C sp3 D sp2 E sp 23 Which of the following molecules has delocalized bonds I ozone O3 II hydrogen cyanide HCN III acetylene C2H2 A I only B II only C III only D I and II only E I and III only 24 How many hybrid orbitals are formed from the combination of one s and one p orbital A 0 B 1 C 2 D 3 E 4 25 Calculate the H for the compound shown below O Br H A 0 48 B 0 52 C 7 3 D 46 3 E 38 6 26 A student has 50 g of each of these molecules in a separate vial Which sample has the greatest number of oxygen atoms 27 Which of the following is the best Lewis dot structure for NO2 A O N O B O N O C O N O D O N O E O N O 28 Rank the following molecules in order of decreasing molecular polarity A I III II B I II III C II III I D III I II E II I III END OF EXAM Practice Exam 2A Scratch Paper 110 Practice Exam 2A Answer …