Which test is positive for all ketones?
a. Schiff's test
b. Iodoform test
c. Tollens' test
d. Semicarbazone test
e. none of these
Answer: d. Semicarbazone test
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CHEM 238
- There are several chemical classification tests that can discern the difference between aldehydes and ketones, and also provide partial structure determination. Identify the components of the iodoform test reagent by dragging the reagent labels into the box.
- The nitrating mixture of concentrated nitric and sulfuric acids is very corrosive. Nitric acid will burn and stain your skin yellow, while sulfuric acid will cause serious dehydrating tissue damage. Which of the following actions should you follow if you spill the nitrating mix on your jeans?
- There are several chemical classification tests that can discern the difference between aldehydes and ketones, and also provide partial structure determination. Identify the components of the Schiff's test reagent by dragging the reagent labels into the box.
- The use of rinse acetone to remove traces of water from glassware is a very common laboratory technique. When performing qualitative tests in glass test tubes, such as Iodoform test or dinitrophenylhydrazine test, why should you avoid rinsing the glassware with acetone prior this experiment?
- Only one aldehyde gives a positive test with the iodoform test. What is the name and structure?
- The safety hazard warning for Acetyl chloride labels it as a lachrymator. Which of the following statements best defines what a lachrymator is?
- A reaction was performed, and the dichloromethane solvent was dried by adding magnesium sulfate drying agent. When the reaction flask was shaken, it was observed that the magnesium sulfate swirled around freely at the bottom of the flask. What does this observation indicate?
- Which of the following statements is false about Grignard Reaction?
- List the procedural steps, from start to finish, that are required to convert dibenzyl ketone and benzil into tetraphenylcyclopentadienone.
- List the procedural steps, from start to finish, that are required to prepare indigo from nitrobenzaldehyde and acetone in base, and then test its ability as a dye.
- List the procedural steps, from start to finish, that are required for the correct use of an automatic micropipette.
- List the procedural steps, from start to finish, that are required in the sodium borohydride reduction of camphor to isoborneol.
- What does the value of the molar extinction coefficient, ε, reveal?
- What are min and max values of wavelength in UVB region?
- List the procedural steps, from start to finish, that are required to generate a low molecular mass ester, and to characterize it by smell.
- How does adding a Brønsted acid help the reaction?
- List the procedural steps, from start to finish, that are required to convert benzoic acid into methyl benzoate via a Fischer esterification.
- Methyl benzoate undergoes a nitration by electrophilic aromatic substitution when reacted with a mixture of concentrated nitric and sulfuric acids. List the procedural steps in order to convert methyl benzoate into methyl nitrobenzoate.
- 2-Butanone is converted into 3-methyl-3-hexanol using a Grignard reagent prepared from 1-bromopropane and magnesium metal in THF solution. List the procedural steps required to collect the alcohol product by microdistillation.
- In a Grignard reagent, the bond between carbon and magnesium is covalent, but highly polarized. Complete the sentence: Therefore, the carbon reacts as if it was a ________ and is a __________ and a good ________.
- Grignard reactions are highly exothermic and are performed in ether solvent. There is a real risk of fire during this reaction. In the case that a fire should occur in your distillation apparatus, what is the best course of action?
- Why are ethers commonly used as a solvent for Grignard reagent preparations?
- List the procedural steps, from start to finish, that are required to convert 2-butanone into 3-methyl-3-hexanol using a Grignard reagent prepared from 1-bromopropane and magnesium metal.
- During the preparation of a tertiary alcohol by a Grignard reaction, the reaction mixture was shaken with saturated sodium chloride solution. What is the purpose of the saturated sodium chloride solution?
- Benzophenone reacts with phenylmagnesium bromide in ether solution to make triphenylmethanol after acid workup. Which of the following experimental mistakes will decrease the effectiveness of a Grignard reaction?