Assertion: Bromobenzene upon reaction with `Br_(2)//Fe` gives 1,4-dibromobenzene as the major product
Reason In bromobenzene the inductive effect of the bromo group is more dominant than the mesomeric effect in directing the incoming electrophile .
Assertion: Bromobenzene upon reaction with `Br_(2)//Fe` gives 1,4-dibromobenzene as the major product
Reason In bromobenzene the inductive effect of the bromo group is more dominant than the mesomeric effect in directing the incoming electrophile .
Reason In bromobenzene the inductive effect of the bromo group is more dominant than the mesomeric effect in directing the incoming electrophile .
A
Statement 1: is true Statement 2: is true, Statement 2 is the correct explainion of Statement 1
B
Statement 1 is true, Statement 2 is true, Statement 2 is not the correct explainion fo Statement 1.
C
Statement 1 is true, Statement 2 is false.
D
Statement 1 is false, Statement 2 is true.
Text Solution
AI Generated Solution
To solve the question, we need to analyze both the assertion and the reason provided.
### Step 1: Analyze the Assertion
The assertion states that bromobenzene reacts with bromine in the presence of iron to yield 1,4-dibromobenzene as the major product.
- **Bromobenzene Structure**: Bromobenzene is a benzene ring with a bromine atom attached. The reaction involves electrophilic aromatic substitution where the bromine (Br₂) is activated by iron (Fe) to generate a bromonium ion (Br⁺) that acts as the electrophile.
- **Electrophilic Attack**: The electrophile can attack the benzene ring at the ortho (2-position) or para (4-position) relative to the existing bromine atom.
...
Topper's Solved these Questions
AROMATIC COMPOUNDS AND ALKYL AND ARYL HALIDES
CENGAGE CHEMISTRY ENGLISH|Exercise Archives Subjective|18 VideosAROMATIC COMPOUNDS AND ALKYL AND ARYL HALIDES
CENGAGE CHEMISTRY ENGLISH|Exercise Archives Subjective Type|4 VideosAROMATIC COMPOUNDS AND ALKYL AND ARYL HALIDES
CENGAGE CHEMISTRY ENGLISH|Exercise Archives Fill In Theblanks|12 VideosAPPENDIX INORGANIC VOLUME 2
CENGAGE CHEMISTRY ENGLISH|Exercise Short Answer Type|179 VideosBIOMOLECULES
CENGAGE CHEMISTRY ENGLISH|Exercise Exercises Archives (Analytical And Descriptive)|8 Videos
Similar Questions
Explore conceptually related problems
Assertion:2-Bromobutane on reaction with sodium ethoxide in ethanol gives 1-butene as a major product Reason:1-butene is more stable than 2-butene.
It is not always easy to predict the position of attack on multiply substituted benzene. If the benzene ring bears different ortho//para directing group at the 1 and 4 positions, the position of further substitution is not immediately clear. Sometimes steric effects determine the outcome. In other cases, electronic factors determine the outcome, and further reaction will be at the position activated by the more strongly activating group. Some substituens are so strongly activating that no catalyst is needed, and it is often diffcult to stop substitution after mono substituion. Mild condition are needed to restrict the reaction to mono-substitution. It is possible to reduce the activity such groups by side chain reaction so that the reaction can be stopped use can sometimes be made of removable blocking groups on the ring. Which of the following is the correct major product ?
It is not always easy to predict the position of attack on multiply substituted benzene. If the benzene ring bears different ortho//para directing group at the 1 and 4 positions, the position of further substitution is not immediately clear. Sometimes steric effects determine the outcome. In other cases, electronic factors determine the outcome, and further reaction will be at the position activated by the more strongly activating group. Some substituens are so strongly activating that no catalyst is needed, and it is often diffcult to stop substitution after mono substituion. Mild condition are needed to restrict the reaction to mono-substitution. It is possible to reduce the activity such groups by side chain reaction so that the reaction can be stopped use can sometimes be made of removable blocking groups on the ring. Which of the following side reaction//s can be used to reduce the activity of strongly activating groups like -OH ?
It is not always easy to predict the position of attack on multiply substituted benzene. If the benzene ring bears different ortho//para directing group at the 1 and 4 positions, the position of further substitution is not immediately clear. Sometimes steric effects determine the outcome. In other cases, electronic factors determine the outcome, and further reaction will be at the position activated by the more strongly activating group. Some substituens are so strongly activating that no catalyst is needed, and it is often diffcult to stop substitution after mono substituion. Mild condition are needed to restrict the reaction to mono-substitution. It is possible to reduce the activity such groups by side chain reaction so that the reaction can be stopped use can sometimes be made of removable blocking groups on the ring. Which of the following synthesis could be done in the ring step ?
Consider a solution of CH_3COONH_4 which is a salt weak acid and weak base. The equilibrium involved in the solutions are : CH_3COO^(-)+H_2OhArrCH_3COOH+OH^(-) " ........"(i) NH_(4)^(+)+H_(2)hArrNH_(4)OH+H^(+)" ........"(ii) H^(+)+OH^(-)hArrH_(2)O" ........"(iii) If we add these reactions, then the net reaction is : CH_(3)COO^(-)+H_(2)^(+)+H_(2)OhArrCH_(3)COOH+NH_(4)OH" ........"(iv) Both CH_(3)COO^(-) and NH_(4)^(+) get hydrolysed independently and their hydrolysis depends on : (a) their initial concentration (b) The value of K_(h) which is (K_(w))/(K_(a)) for CH_(3)COO^(-) and (K_(w))/(K_(b)) for NH_(4)^(+) . Since both of the ions were produced form the salt, their initial concertration are same. Therefore, unless and until the value of (K_(w))/(K_(a)) or K_(a) and K_(b) is same, the degree of hydrogen of ions can't be same. To explain why we assume that degree of hydrolysis of cation and anion is same, we needed to now look at the third reaction i.e.,combination of H^(+) and OH^(-) ions. It is obvious that this reaction happens only because one reaction produced H^(+) ion and the other prodcued OH^(-) ions. We can also note that this reaction causes both the hydrolysis reaction to occur more since their product ions are being consumed. Keep this in mind that the equilibrium which has smaller value of the equilibrium constant is affected more by the common ion effect. For the same reason if for any reson a reaction is made to occur to a greater extent by the consumption of any of the prodcut ion, the reaction with the smaller value of equilibrium constant tends to get affected more. Therefore, we conclude that firstly the hydroylsis of both the ions occurs more in the presence of each other (due to consumption of the product ions) than in each other's absence. Secondly,the hydroylsis of the ion which occurs to a lesser extent (due to smaller value of K_(h)) is affected more than the one whole K_(h) is greater. Hence we can see that the degree of hydroylsis of both the ions would be close to each other when they are getting hyderolysed in the presence of each other. In the hydrolysis of salt weak acid and weak base :
Consider a solution of CH_3COONH_4 which is a salt weak acid and weak base. The equilibrium involved in the solutions are : CH_3COO^(-)+H_2OhArrCH_3COOH+OH^(-) " ........"(i) NH_(4)^(+)+H_(2)hArrNH_(4)OH+H^(+)" ........"(ii) H^(+)+OH^(-)hArrH_(2)O" ........"(iii) If we add these reactions, then the net reaction is : CH_(3)COO^(-)+H_(2)^(+)+H_(2)OhArrCH_(3)COOH+NH_(4)OH" ........"(iv) Both CH_(3)COO^(-) and NH_(4)^(+) get hydrolysed independently and their hydrolysis depends on : (a) their initial concentration (b) The value of K_(h) which is (K_(w))/(K_(a)) for CH_(3)COO^(-) and (K_(w))/(K_(b)) for NH_(4)^(+) . Since both of the ions were produced form the salt, their initial concertration are same. Therefore, unless and until the value of (K_(w))/(K_(a)) or K_(a) and K_(b) is same, the degree of hydrogen of ions can't be same. To explain why we assume that degree of hydrolysis of cation and anion is same, we needed to now look at the third reaction i.e.,combination of H^(+) and OH^(-) ions. It is obvious that this reaction happens only because one reaction produced H^(+) ion and the other prodcued OH^(-) ions. We can also note that this reaction causes both the hydrolysis reaction to occur more since their product ions are being consumed. Keep this in mind that the equilibrium which has smaller value of the equilibrium constant is affected more by the common ion effect. For the same reason if for any reson a reaction is made to occur to a greater extent by the consumption of any of the prodcut ion, the reaction with the smaller value of equilibrium constant tends to get affected more. Therefore, we conclude that firstly the hydroylsis of both the ions occurs more in the presence of each other (due to consumption of the product ions) than in each other's absence. Secondly,the hydroylsis of the ion which occurs to a lesser extent (due to smaller value of K_(h)) is affected more than the one whole K_(h) is greater. Hence we can see that the degree of hydroylsis of both the ions would be close to each other when they are getting hyderolysed in the presence of each other. For 0.1 M CH_3COONH_(4) salt solution given, K_(a)(CH_(3)COOH)=K_(b)(NH_(4)OH)=2xx10^(-5) . In the case : degree of hydrolysis of cation and anion are :
Treatment of benzene with CO/HCl in the presence of anhydrous "AlCl"_(3)//"CuCl" followed by reaction with Ac_(2)"O"//"NaOAc" gives compound X as the major product. Compound X upon reaction with Br_(2)//Na_(2)CO_(3) , followed by heating at 473 K with moist KOH furnishes Y as the major product. Reaction of X with H_(2)//Pd-C , followed by H_(3)PO_(4) treatment gives Z as the major product. The compound Y is
Treatment of benzene with CO/HCl in the presence of anhydrous "AlCl"_(3)//"CuCl" followed by reaction with Ac_(2)"O"//"NaOAc" gives compound X as the major product. Compound X upon reaction with Br_(2)//Na_(2)CO_(3) , followed by heating at 473 K with moist KOH furnishes Y as the major product. Reaction of X with H_(2)//Pd-C , followed by H_(3)PO_(4) treatment gives Z as the major product. The compound Z is
Hofmann rearrangement In the Hofmann rearrangement an unsubstitued amide is treated with sodium hydroxide and bromine to give a primary amine that has one carbon lesser than starting amide. Gneral reaction: If the migrating group is chiral then its configuration is retained. Electron releasing effects in the migrating group increase reactivity of Hofmann rearangement. Arrange the following amides according to their relative reactivity when reacted with Br_(2) in excess of strong base:
In the following questions , a statement of assertion (A) is followed by a statement of reason (R). A: Addition of Br_2 / H_2O to propene given 1-Bromo propan-2-ol as the major products, R: Addition of Br_2 / H_2O to an alkene is an example of electrophilic addition