Aldehydes Ketones And Carboxylic Acids

Step 1: Analyzing the structure of the compound.
The compound contains an aldehyde group (-CHO) attached to a carbon-carbon double bond, with a hydroxyl group (-OH) attached to the second carbon in the chain. Step 2: Determining the IUPAC name.
To name this compound according to IUPAC rules, we need to identify the longest chain containing the aldehyde group. The aldehyde is on the first carbon, and the hydroxy group is attached to the second carbon. Therefore, the name is 2-Hydroxybutanal. Step 3: Conclusion.
The correct answer is (A) because the IUPAC name is 2-Hydroxybutanal.

Step 1: Understanding formalin.
Formalin is a commonly used disinfectant and preservative, and it is a 40% aqueous solution of methanal (commonly known as formaldehyde). Formaldehyde is a simple aldehyde with the formula . Step 2: Analysis of options.
(A) Formic acid: Formic acid is a different compound with the formula .
(B) Fluoroform: Fluoroform is a different compound with the formula .
(C) 40% aqueous solution of methanal: Correct — Formalin is a 40% aqueous solution of methanal (formaldehyde).
(D) Paraformaldehyde: Paraformaldehyde is a polymer of formaldehyde, not the same as formalin.
Step 3: Conclusion.
The correct answer is (C) because formalin is a 40% aqueous solution of methanal (formaldehyde).