Fall 08: Exam 1. Ch 1-4 100points If you do not want your ...alroche/fall08org1e1.pdf · Fall 08:...
14
Fall 08: Exam 1. Ch 1-4 100points Name If you do not want your graded exam placed in the box outside my office, then please check here 1-15 are True / False. (15pts) 1) The Periodic Table has the elements arranged in increasing atomic number 2) A σ bond is a covalent bond 3) Carbon has a larger atomic radius than Nitrogen 4) Fluorine is more electronegative than Carbon 5) Carbon has a larger atomic radius than Silicon 6) The electron configuration of Be is 1s 2 2s 2 2p 1 7) Carbon has 6 electrons but only 4 valence electrons 8) Cyclobutane has more ring strain than cyclopentane 9) An sp hybridized atom has two unhybridized p orbitals 10) Hexane and cyclohexane are isomers 11) Cyclopentane has zero ring strain 12) Kinetics provide information about the position of equilibrium 13) The lowest energy conformation of butane is anti 14) Pentane has zero ring strain 15) sp 3 hybrid orbitals are of higher energy than sp hybrid orbitals Fall08org1exam1 page1
Transcript of Fall 08: Exam 1. Ch 1-4 100points If you do not want your ...alroche/fall08org1e1.pdf · Fall 08:...
Fall 08: Exam 1. Ch 1-4 100points Name If you do not want your graded exam placed in the box outside my office, then please check here 1-15 are True / False. (15pts) 1) The Periodic Table has the elements arranged in increasing atomic
number 2) A σ bond is a covalent bond 3) Carbon has a larger atomic radius than Nitrogen 4) Fluorine is more electronegative than Carbon 5) Carbon has a larger atomic radius than Silicon 6) The electron configuration of Be is 1s2 2s 22p1
7) Carbon has 6 electrons but only 4 valence electrons 8) Cyclobutane has more ring strain than cyclopentane 9) An sp hybridized atom has two unhybridized p orbitals 10) Hexane and cyclohexane are isomers 11) Cyclopentane has zero ring strain 12) Kinetics provide information about the position of equilibrium 13) The lowest energy conformation of butane is anti 14) Pentane has zero ring strain 15) sp3 hybrid orbitals are of higher energy than sp hybrid orbitals
Fall08org1exam1 page1
16) Draw Lewis structures (lines for bonds and dots for all lone pairs) for the following molecules: (6pts) (a) B(OH)3 (b)
ONH
17) (16pts): For the below molecule, calculate the number of…
N
N
a) carbon atoms b) hydrogen atoms c) nitrogen atoms d) rings e) sp2 hybridized carbons f) sp2 hybridized atoms g) sp3 hybridized atoms h) lone pairs (non bonding pairs) of electrons
Fall08org1exam1 page2
18) (8pts) (i) What is meant by the term Kinetics?
(ii) What is meant by Structural Isomer?
(iii) What two components contribute to ring strain?
(iv) Provide an everyday example of an increase in Entropy.
19) (12pts): For the below energy level diagram…
a) is this reaction exothermic or endothermic ? b) Will the Equilibrium constant (K) be greater or less than 1.00 ? c) how many transition states are there ? d) how many steps is this multistep reaction ? e) which step is the rate determining step ? f) which is the fastest step ?
Fall08org1exam1 page3
20) Name the following compounds in IUPAC form. (15pts) (a)
(b)
(c)
(d)
(e)
CH2CH3CH3CH2
H
HCH3CH2
CH3
CH3 H
Fall08org1exam1 page4
21) Circle the more stable member of each pair (8pts)
(a)
(b)
(c)
OH
OH
F
H
BrCl
Cl
H
BrF
Br
CH3
CH3Br
(d)
C(CH3)3
H
CH2CH3
H
CH2CH3
H
C(CH3)3
H
22) Draw in the axial C-H bonds on this chair cyclohexane (3pts)
Fall08org1exam1 page5
23) In the lowest energy conformation of trans-1,4-dimethylcyclohexane, how many axial positions are occupied by Hydrogen atoms ? (5pts) 24) In the lowest energy conformation of cis-1,4-dimethylcyclohexane, how many axial positions are occupied by Hydrogen atoms ? (5pts)
Fall08org1exam1 page6
25) Explain why the methyl radical ( •CH3 ) has H-C-H bond angles of 120°. (7pts)
***Bonus question for 2 points***
What is the difference between bond angle and dihedral angle ?
Fall08org1exam1 page7
