Alcohols Phenols And Ethers

Step 1: Understand the role of anhydrous CaCl2.
Anhydrous calcium chloride (CaCl2) is commonly used as a drying agent for liquids, as it absorbs water by forming hydrated calcium chloride.
Step 2: Why it doesn't dry ethyl alcohol.
However, ethyl alcohol (ethanol) contains a hydroxyl group (-OH) that can form hydrogen bonds with calcium chloride, causing it to react with the alcohol. This prevents anhydrous CaCl2 from effectively drying ethanol.
Step 3: Alternative drying agents.
To dry ethanol, substances like molecular sieves or anhydrous magnesium sulfate are more effective, as they do not react with the alcohol.
Final Answer: Anhydrous CaCl2 is not used to dry ethyl alcohol because it reacts with the alcohol, preventing it from absorbing water effectively.
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Step 1: Understanding the structure of alcohols and alkanes.
Alcohols ( ) contain a hydroxyl group (-OH), while alkanes ( ) consist of only carbon and hydrogen atoms. The key factor in solubility is the ability of a molecule to form hydrogen bonds with water molecules.
Step 2: Hydrogen bonding in alcohols.
The hydroxyl group in alcohols is highly polar and can form hydrogen bonds with water molecules. These hydrogen bonds increase the solubility of alcohols in water, as water molecules can interact effectively with alcohol molecules.
Step 3: Lack of hydrogen bonding in alkanes.
Alkanes, on the other hand, are nonpolar and cannot form hydrogen bonds with water. As a result, alkanes are less soluble in water because they cannot interact effectively with water molecules.
Step 4: Conclusion.
Alcohols are more soluble in water than alkanes of the same molecular weight due to the ability of alcohols to form hydrogen bonds with water, which alkanes cannot do.
Final Answer: Alcohols are more soluble in water than alkanes because the hydroxyl group in alcohols forms hydrogen bonds with water molecules, increasing their solubility.
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Step 1: Alcohols.
Alcohols are organic compounds containing one or more hydroxyl (-OH) groups attached to a saturated carbon atom. Alcohols are classified based on the number of hydroxyl groups and the type of carbon to which the hydroxyl group is attached (primary, secondary, or tertiary). Examples: Methanol (CH OH), Ethanol (C H OH).
Step 2: Phenols.
Phenols are organic compounds in which a hydroxyl group (-OH) is attached to a benzene ring (C H ). The hydroxyl group is directly bonded to an aromatic carbon. Examples: Phenol (C H OH), 2,4-Dichlorophenol.
Step 3: Key Differences.
- Structure: Alcohols have the hydroxyl group attached to a saturated carbon atom, whereas phenols have the hydroxyl group attached to an aromatic ring. - Acidity: Phenols are more acidic than alcohols because the negative charge on the oxygen after deprotonation is stabilized by resonance with the benzene ring. Alcohols do not have this resonance stabilization. - Reactivity: Phenols undergo electrophilic substitution reactions due to the presence of the aromatic ring, whereas alcohols mainly undergo substitution or elimination reactions.
Final Answer: Alcohols have a hydroxyl group attached to a saturated carbon, while phenols have a hydroxyl group attached to a benzene ring, making phenols more acidic and reactive.
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Step 1: Determine the molecular formula.
The molecular formula indicates a compound with four carbon atoms, ten hydrogen atoms, and one oxygen atom. This is the formula for alcohols.
Step 2: Identify possible alcohol isomers.
By rearranging the positions of the hydroxyl group (-OH) on the carbon chain and considering possible branching, the following alcohol isomers can be formed: 1. Butan-1-ol (straight-chain) 2. Butan-2-ol (straight-chain) 3. Isobutanol (branched-chain) 4. tert-Butanol (branched-chain) Thus, there are four isomers.
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Step 1: Understand the oxidation reaction.
Methyl alcohol (methanol, ) undergoes oxidation with acidified potassium dichromate ( ), where it is oxidized to formaldehyde (HCHO) and further oxidized to formic acid (HCOOH).
Step 2: Identify the correct product.
When methyl alcohol undergoes oxidation, it is first converted to formaldehyde (HCHO), which is further oxidized to formic acid (HCOOH).
Step 3: Eliminate the incorrect options.
- Option (A) : Incorrect, this is acetone, not the product of methanol oxidation. - Option (B) : Incorrect, this is formaldehyde, an intermediate in the oxidation process. - Option (C) HCOOH: Correct, formic acid is the final product of methanol oxidation. - Option (D) : Incorrect, this is acetic acid, which is produced from ethanol, not methanol.
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Step 1: Understand the function of diethyl ether.
Diethyl ether, commonly known simply as ether, was historically used as an anaesthetic for surgeries due to its ability to cause unconsciousness and loss of sensation.
Step 2: Evaluate the options.
- Option (A) Pain killer: Incorrect, while diethyl ether can relieve pain indirectly by inducing unconsciousness, it is not primarily classified as a pain killer. - Option (B) Hypnotic: Incorrect, although it has hypnotic (sleep-inducing) properties, the term "hypnotic" is more commonly associated with substances specifically designed to induce sleep. - Option (C) Antiseptic: Incorrect, diethyl ether has antiseptic properties, but it is not commonly used for this purpose. - Option (D) Anaesthetic: Correct, diethyl ether is most widely known and used as an anaesthetic, particularly in the past for surgeries.
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