Question 1

Which of the following molecules are deprotonated by ethylmagnesium bromide? A)phenol, PhOH B)propyne, CH₃C$\equiv$CH C)dimethylamine, (CH₃)₂NH D)all of these

Accepted Answer

Ethylmagnesium bromide is a strong base and can deprotonate all of the given molecules: phenol, propyne, and dimethylamine.

Question 2

Which of the following is the best choice of solvent for the formation of phenyllithium by the reaction of bromobenzene with lithium?
A)water
B)ethanol
C)tetrahydrofuran
D)acetic acid

Accepted Answer

Tetrahydrofuran (THF) is commonly used as a solvent for the formation of phenyllithium by the reaction of bromobenzene with lithium. This is because THF is a non-polar solvent that is able to solvate lithium ions and can also serve as a source of protons for the deprotonation of bromobenzene. Water, ethanol, and acetic acid are polar solvents that would not be effective in solvating the lithium ions and could potentially interfere with the reaction.

Question 3

What is the major organic product obtained from the following sequence of reactions? 
A)2-pentanol
B)pentane
C)1-pentene
D)(E)-2-pentene

Accepted Answer

B

Question 4

Which combination(s) of alkyl bromide and epoxide can be used to prepare the following product by addition of the Grignard reagent derived from the alkyl bromide to the epoxide? 
A)only 1
B)only 2
C)only 1 and 3
D)only 2 and 4

Accepted Answer

The answer of Which combination(s) of alkyl bromide and epoxide...

Question 5

Which of the following is the best choice of solvent for the formation of phenylmagnesium bromide by the reaction of bromobenzene with magnesium?
A)water
B)methanol
C)diethyl ether
D)acetic acid

Accepted Answer

Diethyl ether is the best choice of solvent for the formation of phenylmagnesium bromide because it is a non-polar solvent that will dissolve both the organic bromobenzene and the inorganic magnesium, allowing the reaction to take place. Water, methanol, and acetic acid are polar solvents and would not be suitable for this reaction.

Question 6

What is the major organic product obtained from the following sequence of reactions? 
A)1
B)2
C)3
D)4

Accepted Answer

The answer of What is the major organic product obtained...

Question 7

Which of the following mechanisms accounts for the acid-base reaction of ethylmagnesum bromide with acetylene to give acetylide anion? 
A)1
B)2
C)3
D)4

Accepted Answer

The answer of Which of the following mechanisms accounts for...

Question 8

Which of the following alcohols can be prepared from a Grignard reagent and ethylene oxide? 
A)only 1 and 2
B)only 1 and 4
C)only 1, 2 and 3
D)only 2 and 4

Accepted Answer

The answer of Which of the following alcohols can be...

Question 9

Which combination(s) of alkyl bromide and epoxide can be used to prepare the following product by addition of the Grignard reagent derived from the alkyl bromide to the epoxide? 
A)only 1
B)only 2
C)only 1 and 3
D)only 2 and 4

Accepted Answer

The answer of Which combination(s) of alkyl bromide and epoxide...

Question 10

Which of the following alcohols can be prepared from a Grignard reagent and ethylene oxide? 
A)only 1
B)only 1 and 2
C)only 1, 2 and 3
D)1, 2, 3 and 4

Accepted Answer

Grignard reagents react with ethylene oxide to form primary alcohols. Therefore, only options 1 and 2 can be prepared from the given reaction. Option 3 has a secondary alcohol, and option 4 has a tertiary alcohol, which cannot be formed from this reaction. Hence, the correct choice is B) only 1 and 2.

Question 11

What is the major organic product obtained from the following reaction? 
A)1
B)2
C)3
D)4

Accepted Answer

The answer of What is the major organic product obtained...

Question 12

Which of the following compounds is the strongest base? A)CH₃CH₂MgBr B)CH₃CH₂OH C)CH₃CH₂OMgBr D)CH₃CH₃

Accepted Answer

The answer of Which of the following compounds is the...

Question 13

Which of the following bonds has the most ionic character?
A)C-Al
B)C-Hg
C)C-Mg
D)C-Zn

Accepted Answer

The greater the difference in electronegativity between the two atoms, the more ionic character the bond will have. Among the options given, Mg has the greatest difference in electronegativity when compared to F, hence the bond between Mg and F will have the most ionic character.

Question 14

What is the major organic product obtained from the following sequence of reactions? 
A)1
B)2
C)3
D)4

Accepted Answer

The answer of What is the major organic product obtained...

Question 15

What is the major organic product obtained from the following reaction? 
A)1
B)2
C)3
D)4

Accepted Answer

The reactant is an alkene with four carbons, and it undergoes a halogenation reaction with Br2 in CHCl3. This results in the addition of a Br atom to each of the two carbons in the double bond. The product is a vicinal dihalide with two Br atoms on adjacent carbons. The correct answer is therefore B) 2.

Question 16

What term describes the process whereby an alkyl halide undergoes reaction with magnesium metal to give an alkylmagnesium bromide (Grignard reagent)?
A)nucleophilic substitution
B)electrophilic addition
C)oxidative addition
D)reductive elimination

Accepted Answer

The process is known as oxidative addition. This is because the magnesium metal is oxidized (loses electrons) while inserting itself into the carbon-halogen bond of the alkyl halide, resulting in the formation of an alkylmagnesium halide, commonly referred to as a Grignard reagent.

Question 17

Which of the following compounds is the strongest base? A)NaOH B)NH₃ C)CH₃Li D)CH₃OH

Accepted Answer

The compound CH3Li is a strong base due to the presence of the highly electronegative element lithium (Li). This element attracts electron density towards itself, creating a negative charge on the other end of the molecule, which can readily accept protons (H+ ions) to form a stable product. NaOH is also a strong base, but it is not as strong as CH3Li. The other two compounds are not bases; NHSO4H is an acid and CH3OH is a neutral molecule.

Question 18

What is the major organic product obtained from the following sequence of reactions? 
A)2-methylbutane
B)3-methyl-1-butanol
C)3-methyl-2-butene
D)3-methyl-2-butanol

Accepted Answer

The answer of What is the major organic product obtained...

Question 19

What is the change in oxidation state of the metal when magnesium reacts with an alkyl bromide to give an alkylmagnesium bromide (Grignard reagent)?
A)0 $\rarr$ +1
B)0 $\rarr$ +2
C)0 $\rarr$ -1
D)0 $\rarr$ -2

Accepted Answer

When magnesium reacts with an alkyl bromide to form an alkylmagnesium bromide (Grignard reagent), the magnesium undergoes a change in oxidation state from 0 to +2. Therefore, the correct choice is B, where the change in oxidation state is +2.

Question 20

Which of the following bonds has the most ionic character?
A)C-Sn
B)C-Cu
C)C-Zn
D)C-Li

Accepted Answer

The degree of ionic character in a bond depends on the electronegativity difference between the two atoms. Li has a low electronegativity (0.98) compared to F (3.98), which results in a large electronegativity difference between Li and F. Therefore, the bond between Li and F in CF1F1F1S1F1F1F10Li is expected to have the most ionic character among the given options.

Quiz 15: An Introduction to Organometallic Compounds

Which of the following molecules are deprotonated by ethylmagnesium bromide?

Which of the following is the best choice of solvent for the formation of phenyllithium by the reaction of bromobenzene with lithium?

What is the major organic product obtained from the following sequence of reactions?

Which combination(s) of alkyl bromide and epoxide can be used to prepare the following product by addition of the Grignard reagent derived from the alkyl bromide to the epoxide?

Which of the following is the best choice of solvent for the formation of phenylmagnesium bromide by the reaction of bromobenzene with magnesium?

What is the major organic product obtained from the following sequence of reactions?

Which of the following mechanisms accounts for the acid-base reaction of ethylmagnesum bromide with acetylene to give acetylide anion?

Which of the following alcohols can be prepared from a Grignard reagent and ethylene oxide?

Which combination(s) of alkyl bromide and epoxide can be used to prepare the following product by addition of the Grignard reagent derived from the alkyl bromide to the epoxide?

Which of the following alcohols can be prepared from a Grignard reagent and ethylene oxide?

What is the major organic product obtained from the following reaction?

Which of the following compounds is the strongest base?

Which of the following bonds has the most ionic character?

What is the major organic product obtained from the following sequence of reactions?

What is the major organic product obtained from the following reaction?

What term describes the process whereby an alkyl halide undergoes reaction with magnesium metal to give an alkylmagnesium bromide (Grignard reagent) ?

Which of the following compounds is the strongest base?

What is the major organic product obtained from the following sequence of reactions?

What is the change in oxidation state of the metal when magnesium reacts with an alkyl bromide to give an alkylmagnesium bromide (Grignard reagent) ?

Which of the following bonds has the most ionic character?