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OCHEM LAB FINAL EXAM REVIEW STUDY GUIDE
EXAM WITH COMPLETE 450 QUESTIONS AND WELL
ELABORATED ANSWERS JUST RELEASED
QUESTION: In the Biodiesel lab, What is the purpose of adding acetic acid (vinegar) to the
reaction flask after the reaction is complete?
a. Used as a drying agent
b. Neutralize the acid before extraction
c. Neutralize the base before extraction - ANSWER✔✔Neutralize the base before extraction
QUESTION: In the Biodiesel lab, Carbonic acid is unstable in water and will spontaneously
decompose into _____ and ____
a. Carbon monoxide and water
b. Carbon dioxide and water
c. Acetic acid and water - ANSWER✔✔Carbon dioxide and water
QUESTION: True/False We need to run the product through the pipette that contains sodium
sulfate to remove the last traces of water - ANSWER✔✔True
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QUESTION: True/False Biodiesel is said to be "carbon neutral" that is it neither adds to or
subtracts from the amount of carbon dioxide in the atmosphere - ANSWER✔✔True
QUESTION: In the Biodiesel lab, What is the byproduct that is obtained in this reaction
a. Triglyceride
b. Methyl ester
c. Methanol
d. Glycerol - ANSWER✔✔Glycerol
QUESTION: In the TLC lab, the stationary phase for the experiment is - ANSWER✔✔Silica
QUESTION: In the TLC lab, the mobile phase for the experiment is - ANSWER✔✔0.5% acetic
acid in ethyl acetate
QUESTION:Which technique will you use to determine the purity of a solid sample?
a. mixed melting point
b. melting point
c. boiling point
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d. mixed boiling point - ANSWER✔✔melting point
QUESTION: In the meling and boiling point lab, which technique did you use to determine the
identity of a solid sample?
a. mixed melting point
b. melting point
c. boiling point
d. mixed boiling point - ANSWER✔✔mixed melting point
QUESTION: will an impurity increase or decrease the melting point temperature of a pure
sample?
a. increase
b. decrease - ANSWER✔✔decrease
QUESTION: will an impurity increase or decrease the melting point range of a pure sample?
a. increase
b. decrease - ANSWER✔✔increase
QUESTION: Which technique will you use to determine the identity of a liquid sample?
a. mixed melting point
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b. melting point
c. boiling point
d. mixed boiling point - ANSWER✔✔boiling point
QUESTION: What should the melting point range be for a pure substance?
a. 3-5 degrees C
b. 2-4 degrees C
c. 5-10 degrees C
d. 1-2 degrees C - ANSWER✔✔1-2 degrees C
QUESTION: In this experiment, the thermometer bulb should be positioned in the vapor and
not in the liquid to determine the boiling point of your liquid.
a. True
b. False - ANSWER✔✔True
QUESTION: What is the purpose of wrapping the boiling point apparatus with aluminum foil?
a. to maximize heat loss
b. to maximize cooling
c. to minimize heat loss
OCHEM LAB FINAL EXAM REVIEW STUDY GUIDE
EXAM WITH COMPLETE 450 QUESTIONS AND WELL
ELABORATED ANSWERS JUST RELEASED
QUESTION: In the Biodiesel lab, What is the purpose of adding acetic acid (vinegar) to the
reaction flask after the reaction is complete?
a. Used as a drying agent
b. Neutralize the acid before extraction
c. Neutralize the base before extraction - ANSWER✔✔Neutralize the base before extraction
QUESTION: In the Biodiesel lab, Carbonic acid is unstable in water and will spontaneously
decompose into _____ and ____
a. Carbon monoxide and water
b. Carbon dioxide and water
c. Acetic acid and water - ANSWER✔✔Carbon dioxide and water
QUESTION: True/False We need to run the product through the pipette that contains sodium
sulfate to remove the last traces of water - ANSWER✔✔True
, Page 2 of 171
QUESTION: True/False Biodiesel is said to be "carbon neutral" that is it neither adds to or
subtracts from the amount of carbon dioxide in the atmosphere - ANSWER✔✔True
QUESTION: In the Biodiesel lab, What is the byproduct that is obtained in this reaction
a. Triglyceride
b. Methyl ester
c. Methanol
d. Glycerol - ANSWER✔✔Glycerol
QUESTION: In the TLC lab, the stationary phase for the experiment is - ANSWER✔✔Silica
QUESTION: In the TLC lab, the mobile phase for the experiment is - ANSWER✔✔0.5% acetic
acid in ethyl acetate
QUESTION:Which technique will you use to determine the purity of a solid sample?
a. mixed melting point
b. melting point
c. boiling point
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d. mixed boiling point - ANSWER✔✔melting point
QUESTION: In the meling and boiling point lab, which technique did you use to determine the
identity of a solid sample?
a. mixed melting point
b. melting point
c. boiling point
d. mixed boiling point - ANSWER✔✔mixed melting point
QUESTION: will an impurity increase or decrease the melting point temperature of a pure
sample?
a. increase
b. decrease - ANSWER✔✔decrease
QUESTION: will an impurity increase or decrease the melting point range of a pure sample?
a. increase
b. decrease - ANSWER✔✔increase
QUESTION: Which technique will you use to determine the identity of a liquid sample?
a. mixed melting point
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b. melting point
c. boiling point
d. mixed boiling point - ANSWER✔✔boiling point
QUESTION: What should the melting point range be for a pure substance?
a. 3-5 degrees C
b. 2-4 degrees C
c. 5-10 degrees C
d. 1-2 degrees C - ANSWER✔✔1-2 degrees C
QUESTION: In this experiment, the thermometer bulb should be positioned in the vapor and
not in the liquid to determine the boiling point of your liquid.
a. True
b. False - ANSWER✔✔True
QUESTION: What is the purpose of wrapping the boiling point apparatus with aluminum foil?
a. to maximize heat loss
b. to maximize cooling
c. to minimize heat loss
