Part B-Does the information written below this table sound correct? Table 1 – Re
ID: 1018720 • Letter: P
Question
Part B-Does the information written below this table sound correct?
Table 1 – Results
Compound
Time for Color Disappearance
>20 minutes
Ran at 0 °C
Diphenylamine
Instantaneous
(also formed a precipitate)
N/A
Instantaneous
(also formed a precipitate)
Phenol
Instantly lost color and turned yellow. After 30 seconds, turned clear.
N/A
Instantly turned yellow. After 52 seconds, turned clear.
N-Methylanaline
Instant color disappearance
N/A
Color disappearance after 60 seconds
Diphenylether
After 30 seconds, lost color and turned yellow
N/A
N/A
Anisole
Instant change to pale orange and after 150 seconds, turned yellow
N/A
N/A
Acetanilide
Turned pale orange at 90 seconds
Remained pale orange (some reactivity but not complete)
N/A
4-Bromophenol
Was pale orange at 180 seconds and at 5 minutes
Remained pale orange (some reactivity but not complete)
N/A
4-Hydroxybenzoic acid
Faded to orange at 180 seconds and stayed orange after 5 minutes
Turned a pale orange at 20 minutes
N/A
Bromobenzene
Red-orange at 5 minutes
Remained orange-red at 20 minutes
N/A
Benzoic Acid
Red-orange at 5 minutes
Remained orange-red at 20 minutes
N/A
Nitrobenzene
No reaction after 5 minutes
No reaction after 20 minutes
N/A
Both the diphenylether and the anisole lost the red color of the bromine and turned a yellow color at 30 seconds and 150 seconds respectively. Both substituents were ortho/para activators and reactivity rates were expected to be fast, yet still slower than the rates of the first three aromatic compounds (diphenylamine, phenol, and N-methylaniline), which had greater activating strengths. Interestingly, it appeared that the extra phenyl on the diphenylether had more of an impact on the speed of the rate than did the methyl group on the anisole. This same effect was also noted when comparing the extra phenyl on the diphenylamine to the methyl group on the N-methylaniline.
The next fastest reacting group of aromatic compounds consisted of acetanilide, 4-bromophenol, and 4-hydroxybenzoic acid. Acetanilide is an ortho/para activator that is not as strong an activator as the first five aromatic compounds talked about; therefore, it was reasonable that acetanilide reacted when it did (pale orange at 90 seconds). Both 4-bromophenol and 4-hydroxybenzoic acid contained a strong activating substituent, the –OH (ortho/para); however, they also both contained a deactivating substituent, the –Br and the carbonyl group. The 4-bromophenol turned pale orange after 180 seconds, while the 4-hydroxybenzoic acid faded to orange at 180 seconds and continued to fade to pale orange by 20 minutes. While both the –Br and the carbonyl group substituents are electron withdrawing groups, –Br is less deactivating than the carboxylic acid, it is ortho/para directing, and it can have stabilization effects similar to the electron donating groups; this all makes it sensible that the 4-bromophenol reacted faster than the 4-hydroxybenzoic acid (meta directing). It was also logical that the acetanilide reacted faster than the 4-bromophenol and the 4-hydroxybenzoic acid as it did not contain any deactivating groups that would have lowered electron density and made it less reactive.
Table 1 – Results
Compound
Time for Color Disappearance
>20 minutes
Ran at 0 °C
Diphenylamine
Instantaneous
(also formed a precipitate)
N/A
Instantaneous
(also formed a precipitate)
Phenol
Instantly lost color and turned yellow. After 30 seconds, turned clear.
N/A
Instantly turned yellow. After 52 seconds, turned clear.
N-Methylanaline
Instant color disappearance
N/A
Color disappearance after 60 seconds
Diphenylether
After 30 seconds, lost color and turned yellow
N/A
N/A
Anisole
Instant change to pale orange and after 150 seconds, turned yellow
N/A
N/A
Acetanilide
Turned pale orange at 90 seconds
Remained pale orange (some reactivity but not complete)
N/A
4-Bromophenol
Was pale orange at 180 seconds and at 5 minutes
Remained pale orange (some reactivity but not complete)
N/A
4-Hydroxybenzoic acid
Faded to orange at 180 seconds and stayed orange after 5 minutes
Turned a pale orange at 20 minutes
N/A
Bromobenzene
Red-orange at 5 minutes
Remained orange-red at 20 minutes
N/A
Benzoic Acid
Red-orange at 5 minutes
Remained orange-red at 20 minutes
N/A
Nitrobenzene
No reaction after 5 minutes
No reaction after 20 minutes
N/A
Explanation / Answer
Correct