Picric acid (2,4,6-trinitrophenol) is prepared from phenol by nitration, where phenol reacts with a mixture of concentrated nitric acid and sulfuric acid. The sulfuric acid serves as a dehydrating agent and provides a medium for the nitration reaction. The modern method involving concentrated sulfurRead more
Picric acid (2,4,6-trinitrophenol) is prepared from phenol by nitration, where phenol reacts with a mixture of concentrated nitric acid and sulfuric acid. The sulfuric acid serves as a dehydrating agent and provides a medium for the nitration reaction. The modern method involving concentrated sulfuric acid is favored for better yield because sulfuric acid helps maintain a more anhydrous environment, reducing side reactions and enhancing the efficiency of nitration. Additionally, concentrated sulfuric acid aids in the formation of the nitronium ion, a key intermediate in the nitration process, leading to improved selectivity and higher yields of picric acid.
The -OH group in phenol enhances its reactivity in halogenation reactions with bromine in solvents of low polarity. Phenol's oxygen donates electron density through resonance, activating the ring and making it more nucleophilic. This facilitates electrophilic attack by bromine, leading to brominatioRead more
The -OH group in phenol enhances its reactivity in halogenation reactions with bromine in solvents of low polarity. Phenol’s oxygen donates electron density through resonance, activating the ring and making it more nucleophilic. This facilitates electrophilic attack by bromine, leading to bromination. Unlike benzene, phenol doesn’t require a Lewis acid like FeBr₃ for bromine polarization. The oxygen lone pairs in phenol can directly interact with bromine, facilitating bromine’s attack on the ring. The -OH group’s electron-donating nature increases the nucleophilicity of the ring, promoting halogenation without the need for an additional Lewis acid catalyst.
When phenol reacts with bromine water, the main product formed is 2,4,6-tribromophenol. This is due to the electrophilic aromatic substitution of bromine on the phenolic ring. The experimental conditions favoring the formation of 2,4,6-tribromophenol involve using excess bromine and maintaining sligRead more
When phenol reacts with bromine water, the main product formed is 2,4,6-tribromophenol. This is due to the electrophilic aromatic substitution of bromine on the phenolic ring. The experimental conditions favoring the formation of 2,4,6-tribromophenol involve using excess bromine and maintaining slightly acidic conditions. The excess bromine ensures multiple brominations on the aromatic ring, and the slightly acidic environment helps to protonate the phenoxide ion, making it more reactive towards electrophilic attack by bromine. These conditions promote the substitution of all available hydrogen atoms on the phenolic ring, resulting in the formation of 2,4,6-tribromophenol.
In Kolbe's reaction, phenol undergoes electrophilic aromatic substitution with sodium phenoxide (generated from phenol by reacting it with sodium hydroxide). The main product is salicylic acid. The phenoxide ion is more reactive than phenol due to resonance stabilization. The negative charge on oxygRead more
In Kolbe’s reaction, phenol undergoes electrophilic aromatic substitution with sodium phenoxide (generated from phenol by reacting it with sodium hydroxide). The main product is salicylic acid. The phenoxide ion is more reactive than phenol due to resonance stabilization. The negative charge on oxygen can delocalize onto the aromatic ring, creating a more stable intermediate. This enhanced stability makes the phenoxide ion a better nucleophile in electrophilic aromatic substitution reactions. The nucleophilic attack on carbon dioxide (CO₂) results in the formation of salicylate, and subsequent acidification produces salicylic acid as the primary product.
Unicellular organisms primarily remove metabolic wastes through simple diffusion. As single-celled entities, they lack specialized excretory organs. Waste products, such as carbon dioxide and ammonia, diffuse out of the cell into the surrounding environment. Additionally, some unicellular organismsRead more
Unicellular organisms primarily remove metabolic wastes through simple diffusion. As single-celled entities, they lack specialized excretory organs. Waste products, such as carbon dioxide and ammonia, diffuse out of the cell into the surrounding environment. Additionally, some unicellular organisms release waste materials through processes like exocytosis, where waste-containing vesicles fuse with the cell membrane, expelling the waste outside. This uncomplicated diffusion-based excretion is sufficient for the relatively low metabolic waste production in unicellular organisms, ensuring the maintenance of a favorable internal environment for cellular functions.
How is picric acid (2,4,6-trinitrophenol) typically prepared from phenol, and why is the modern method involving concentrated sulfuric acid utilized for better yield?
Picric acid (2,4,6-trinitrophenol) is prepared from phenol by nitration, where phenol reacts with a mixture of concentrated nitric acid and sulfuric acid. The sulfuric acid serves as a dehydrating agent and provides a medium for the nitration reaction. The modern method involving concentrated sulfurRead more
Picric acid (2,4,6-trinitrophenol) is prepared from phenol by nitration, where phenol reacts with a mixture of concentrated nitric acid and sulfuric acid. The sulfuric acid serves as a dehydrating agent and provides a medium for the nitration reaction. The modern method involving concentrated sulfuric acid is favored for better yield because sulfuric acid helps maintain a more anhydrous environment, reducing side reactions and enhancing the efficiency of nitration. Additionally, concentrated sulfuric acid aids in the formation of the nitronium ion, a key intermediate in the nitration process, leading to improved selectivity and higher yields of picric acid.
See lessHow does the presence of the -OH group in phenol affect the halogenation reaction with bromine in solvents of low polarity, and why does phenol not require a Lewis acid like FeBr₃ for bromine polarisation?
The -OH group in phenol enhances its reactivity in halogenation reactions with bromine in solvents of low polarity. Phenol's oxygen donates electron density through resonance, activating the ring and making it more nucleophilic. This facilitates electrophilic attack by bromine, leading to brominatioRead more
The -OH group in phenol enhances its reactivity in halogenation reactions with bromine in solvents of low polarity. Phenol’s oxygen donates electron density through resonance, activating the ring and making it more nucleophilic. This facilitates electrophilic attack by bromine, leading to bromination. Unlike benzene, phenol doesn’t require a Lewis acid like FeBr₃ for bromine polarization. The oxygen lone pairs in phenol can directly interact with bromine, facilitating bromine’s attack on the ring. The -OH group’s electron-donating nature increases the nucleophilicity of the ring, promoting halogenation without the need for an additional Lewis acid catalyst.
See lessWhen phenol reacts with bromine water, what is the main product formed, and what experimental conditions favor the formation of 2,4,6-tribromophenol?
When phenol reacts with bromine water, the main product formed is 2,4,6-tribromophenol. This is due to the electrophilic aromatic substitution of bromine on the phenolic ring. The experimental conditions favoring the formation of 2,4,6-tribromophenol involve using excess bromine and maintaining sligRead more
When phenol reacts with bromine water, the main product formed is 2,4,6-tribromophenol. This is due to the electrophilic aromatic substitution of bromine on the phenolic ring. The experimental conditions favoring the formation of 2,4,6-tribromophenol involve using excess bromine and maintaining slightly acidic conditions. The excess bromine ensures multiple brominations on the aromatic ring, and the slightly acidic environment helps to protonate the phenoxide ion, making it more reactive towards electrophilic attack by bromine. These conditions promote the substitution of all available hydrogen atoms on the phenolic ring, resulting in the formation of 2,4,6-tribromophenol.
See lessDescribe the electrophilic aromatic substitution in Kolbe’s reaction with phenoxide ion generated from phenol. What is the main product, and why is the phenoxide ion more reactive than phenol in this reaction?
In Kolbe's reaction, phenol undergoes electrophilic aromatic substitution with sodium phenoxide (generated from phenol by reacting it with sodium hydroxide). The main product is salicylic acid. The phenoxide ion is more reactive than phenol due to resonance stabilization. The negative charge on oxygRead more
In Kolbe’s reaction, phenol undergoes electrophilic aromatic substitution with sodium phenoxide (generated from phenol by reacting it with sodium hydroxide). The main product is salicylic acid. The phenoxide ion is more reactive than phenol due to resonance stabilization. The negative charge on oxygen can delocalize onto the aromatic ring, creating a more stable intermediate. This enhanced stability makes the phenoxide ion a better nucleophile in electrophilic aromatic substitution reactions. The nucleophilic attack on carbon dioxide (CO₂) results in the formation of salicylate, and subsequent acidification produces salicylic acid as the primary product.
See lessHow do unicellular organisms typically remove metabolic wastes?
Unicellular organisms primarily remove metabolic wastes through simple diffusion. As single-celled entities, they lack specialized excretory organs. Waste products, such as carbon dioxide and ammonia, diffuse out of the cell into the surrounding environment. Additionally, some unicellular organismsRead more
Unicellular organisms primarily remove metabolic wastes through simple diffusion. As single-celled entities, they lack specialized excretory organs. Waste products, such as carbon dioxide and ammonia, diffuse out of the cell into the surrounding environment. Additionally, some unicellular organisms release waste materials through processes like exocytosis, where waste-containing vesicles fuse with the cell membrane, expelling the waste outside. This uncomplicated diffusion-based excretion is sufficient for the relatively low metabolic waste production in unicellular organisms, ensuring the maintenance of a favorable internal environment for cellular functions.
See less