The following questions (1-9) are multiple choice. For each question you are asked to identify your answer by
circling the response. (27 pts)
1. Shown below are NFPA Labels for three solvents whose boiling points are above 100 ºC. Which poses the
lowest health hazard? (4 pts)
a) b) c)
Ethylene glycol Dimethylsulfoxide Toluene
(bp 195-198 ºC) (bp 189 ºC) (bp 110-111 ºC)
2. The purpose of the vacuum pump used with the rotary evaporator is ______. (4 pts)
a) to draw vapors away from the vessel containing your product.
b) to lower the boiling point of the solvent.
c) to prevent exposure of students to harmful vapors.
d) to trap vapors from the vessel containing your product.
3. Which compound has the highest melting point? (3 pts)
a) b) c) d)
CH3 OH I Cl
MW = 150.26 MW = 152.23 MW = 262.13 MW = 170.68
mp 119 ºC mp 247 ºC mp 74 ºC mp 169 ºC
4. Which of the following compounds has the lowest melting point? (3 pts)
a) O b) O c) O
H3CO O2N N
OCH2CH3 OCH2CH3 OCH2CH3
MW = 165 MW = 195 MW = 175
mp 88-90 ºC mp 55-59 ºC mp 52-54 ºC
1
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, 5. Which of the following has the lowest boiling point? (3 pts) – Any answer gets full credit.
a) b) c) d)
O
O N HO
O OH
MW = 74.12 MW = 88.11 MW = 41.05 MW = 62.07
bp 35 ºC bp 77 ºC 139 ºC 197 ºC
6. In which of the following solvents do you expect methyl gallate to be most soluble? (3 pts)
HO
O
HO
OCH3
HO
methyl gallate
a) b) c) O d)
O H2O
hexane diethyl ether acetone water
(ε = 1.9) (ε = 4.3) (ε = 20.7) (ε = 80)
7. The melting range of a compound made in the lab was found to be 112-114 ºC. The literature value for the
melting point of same compound is 125 ºC. Which is (are) true of the sample? (3 pts)
a) The sample is pure.
b) A mixed melting point determination is needed confirm the purity of the compound.
c) The sample likely contains impurities.
d) A mixed melting point determination is needed to confirm the identity of the compound.
e) Both (a) and (d) are true.
2
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circling the response. (27 pts)
1. Shown below are NFPA Labels for three solvents whose boiling points are above 100 ºC. Which poses the
lowest health hazard? (4 pts)
a) b) c)
Ethylene glycol Dimethylsulfoxide Toluene
(bp 195-198 ºC) (bp 189 ºC) (bp 110-111 ºC)
2. The purpose of the vacuum pump used with the rotary evaporator is ______. (4 pts)
a) to draw vapors away from the vessel containing your product.
b) to lower the boiling point of the solvent.
c) to prevent exposure of students to harmful vapors.
d) to trap vapors from the vessel containing your product.
3. Which compound has the highest melting point? (3 pts)
a) b) c) d)
CH3 OH I Cl
MW = 150.26 MW = 152.23 MW = 262.13 MW = 170.68
mp 119 ºC mp 247 ºC mp 74 ºC mp 169 ºC
4. Which of the following compounds has the lowest melting point? (3 pts)
a) O b) O c) O
H3CO O2N N
OCH2CH3 OCH2CH3 OCH2CH3
MW = 165 MW = 195 MW = 175
mp 88-90 ºC mp 55-59 ºC mp 52-54 ºC
1
This study source was downloaded by 100000850872992 from CourseHero.com on 03-05-2023 21:14:20 GMT -06:00
https://www.coursehero.com/file/26176578/Sample-Theory-Quiz-1pdf/
, 5. Which of the following has the lowest boiling point? (3 pts) – Any answer gets full credit.
a) b) c) d)
O
O N HO
O OH
MW = 74.12 MW = 88.11 MW = 41.05 MW = 62.07
bp 35 ºC bp 77 ºC 139 ºC 197 ºC
6. In which of the following solvents do you expect methyl gallate to be most soluble? (3 pts)
HO
O
HO
OCH3
HO
methyl gallate
a) b) c) O d)
O H2O
hexane diethyl ether acetone water
(ε = 1.9) (ε = 4.3) (ε = 20.7) (ε = 80)
7. The melting range of a compound made in the lab was found to be 112-114 ºC. The literature value for the
melting point of same compound is 125 ºC. Which is (are) true of the sample? (3 pts)
a) The sample is pure.
b) A mixed melting point determination is needed confirm the purity of the compound.
c) The sample likely contains impurities.
d) A mixed melting point determination is needed to confirm the identity of the compound.
e) Both (a) and (d) are true.
2
This study source was downloaded by 100000850872992 from CourseHero.com on 03-05-2023 21:14:20 GMT -06:00
https://www.coursehero.com/file/26176578/Sample-Theory-Quiz-1pdf/
