Carboxylic Acids

Step 1: IR absorption regions. The O–H stretch in alcohols absorbs around 3700–3500 cm . The O–H stretch in carboxylic acids absorbs in the 3000–2500 cm range due to hydrogen bonding.
Step 2: Conclusion. Thus, carboxylic acids absorb O–H stretch in the range 3000–2500 cm .

Step 1: Naming the compound.
The structure contains a 6-carbon chain with an ester group at the 4th position, which is a methyl ester. The correct IUPAC name follows the naming conventions for esters and ketones.

Step 2: Conclusion.
Thus, the correct IUPAC name is option (D).

Final Answer:

Step 1: Acid strength comparison.
Acid strength is influenced by the electronegativity of the substituents. In this case, HCOOH is the weakest acid compared to others because it lacks strong electron-withdrawing groups.

Step 2: Conclusion.
Thus, the correct answer is option (B).

Final Answer:

Step 1: Purpose of toluene in esterification.
Toluene is used as a solvent in esterification reactions because it helps dissolve both the alcohol and the acid, making the reaction more efficient.

Step 2: Conclusion.
Thus, the correct answer is option (A).

Final Answer:

Step 1: Understanding transesterification.
Transesterification is the process where one ester is converted into another ester, typically using an alcohol as a reactant.

Step 2: Conclusion.
Thus, the correct answer is option (C).

Final Answer:

Step 1: Structures of maleic and fumaric acids.
Both have formula .
Step 2: Difference in arrangement around double bond.
Maleic acid: cis form (COOH groups on same side).
Fumaric acid: trans form (COOH groups on opposite sides).
Step 3: Type of isomerism.
Cis-trans due to restricted rotation around double bond is geometrical isomerism.
Final Answer:

Step 1: Identify alkali formate.
Alkali formate is or .
Step 2: Understand soda lime.
Soda lime is a mixture of NaOH and CaO.
It is generally used for decarboxylation.
Step 3: Reaction of alkali formate with NaOH (soda lime).
When heated, alkali formate decomposes giving hydrogen gas:

Step 4: Conclusion.
Thus the gas evolved is hydrogen.
Final Answer:

Step 1: Reaction (i).
Calcium acetate on dry distillation gives acetone:

So:

Step 2: Reaction (ii).
Acetic acid reduced with gives ethane:

So:

Step 3: Reaction (iii).
Two moles of acetic acid with gives acetic anhydride:

So:

Final Answer:

Step 1: Analyze the reaction.
In this reaction, acetic acid undergoes several transformations. The exact product D will be dependent on the specific reagents used in each step.
Step 2: Conclusion.
After analyzing the complete reaction mechanism, the product D will be formed under these conditions.
Final Answer:

Step 1: Understanding ester basicity.
In esters, the carbonyl oxygen is more basic than the carboxyl oxygen due to its greater ability to donate electron density.

Step 2: Conclusion.
The carbonyl oxygen is more basic, corresponding to option (1).

Step 1: Analyzing the reaction.
The given reactions and the molecular formula suggest that is acetic acid. The reaction with NaHCO shows the presence of a carboxyl group, and the reduction to an achiral compound supports this.

Step 2: Conclusion.
The correct compound is acetic acid, corresponding to option (1).

Step 1: Understanding the reaction.
The reaction between carboxylic acids and sodium bicarbonate leads to the formation of carbon dioxide and the corresponding sodium salt. The reaction does not involve the formation of carbon.

Step 2: Conclusion.
The correct product of the reaction is and sodium salt, corresponding to option (1).

Step 1: Naming the Compound.
Valeric acid is a carboxylic acid with the formula , and its IUPAC name is butanoic acid.
Step 2: Conclusion.
The correct answer is (B), Butanoic acid.

Step 1: Cannizzaro Reaction.
The Cannizzaro reaction is a base-induced disproportionation of non-enolizable aldehydes, resulting in the formation of an alcohol and an acid, but not specifically introducing a carboxyl group ( ). The other reactions are directly involved in the introduction of the carboxyl group.
Step 2: Conclusion.
The correct answer is (A), Cannizzaro reaction.

Step 1: Role of Pyridine in Esterification.
Pyridine acts as both a base to remove HCl and a nucleophile to react with acid chloride, forming an acylpyridinium ion, which facilitates the esterification reaction.
Step 2: Conclusion.
The correct answer is (C), both (a) and (b).

Step 1: Decarboxylation Mechanism.
Decarboxylation typically occurs when an unsaturated acid can stabilize the leaving group. The large size of the t-butyl group hinders the departure of the group.
Step 2: Conclusion.
The correct answer is (A), t-butyl group has large size and does not let the group to leave.

Step 1: Anhydride Formation.
Anhydrides are formed by the dehydration of carboxylic acids. Oxalic acid (I) and succinic acid (II) can form anhydrides. Benzoic acid (III) and phthalic acid (IV) are less likely to form anhydrides.
Step 2: Conclusion.
The correct answer is (C), I & II.

The uncertainty principle relates the uncertainty in position and momentum. Since the mass of the helium atom is larger than that of the electron, the uncertainty in its momentum is smaller. Therefore, the minimum uncertainty in the momentum of the helium atom is .

Step 2: Conclusion.
Thus, the correct answer is .