Benzaldehyde is most affected by the mesomeric effect due to the presence of the carbonyl group which can participate in resonance.

Benzene is highly stabilized by resonance due to its delocalized pi electrons.

Phenol is not classified as an alcohol because it has an aromatic ring, while the others are aliphatic alcohols.

Phenol is not classified as an alcohol because it has an aromatic ring, while the others are aliphatic alcohols.

Cyclooctatetraene is not aromatic because it does not satisfy Huckel's rule and does not have a planar structure.

Cyclooctatetraene is not aromatic because it does not satisfy Huckel's rule; it is non-planar and does not have a continuous ring of p orbitals.

HCl is a polar molecule due to the difference in electronegativity between hydrogen and chlorine.

Chlorofluorocarbons (CFCs) are known to deplete the ozone layer by breaking down ozone molecules in the stratosphere.

Chlorofluorocarbons (CFCs) are known to deplete the ozone layer by breaking down ozone molecules in the stratosphere.

Phenol is stabilized by the +M effect due to the presence of the -OH group which donates electron density.

Propyne is the most acidic due to the sp hybridization of the carbon atom involved in the triple bond.

Hydrogen peroxide (H2O2) is commonly used as a bleaching agent.

Iron is used as a catalyst in the Haber process for the synthesis of ammonia from nitrogen and hydrogen.

Calcium chloride is commonly used as a desiccant due to its hygroscopic nature.

Carbon tetrachloride is commonly used as a dry cleaning solvent.

Calcium chloride (CaCl2) is commonly used as a drying agent due to its hygroscopic nature.

Boric acid is commonly used as a fire retardant due to its ability to inhibit combustion.

Vanillin is the primary component of the extract of the vanilla bean and is used as a flavoring agent.

Carotenoids are natural pigments used as food colorants.

Sodium borohydride (NaBH4) is commonly used as a reducing agent.

Aspartame is a widely used artificial sweetener in many food products.

Both Aspirin and Ibuprofen are commonly used analgesics that help relieve pain.

Ethanol is commonly used as an antiseptic due to its ability to kill bacteria and viruses.

Aspartame is a widely used artificial sweetener that is approximately 200 times sweeter than sucrose.

Zinc reacts with hydrochloric acid (HCl) to produce hydrogen gas.

Sodium hydroxide is used in the saponification process to produce soap from fats and oils.

Metformin is a medication commonly prescribed for the management of type 2 diabetes.

All of the listed compounds are antacids used to treat heartburn.

Benzaldehyde shows a -I effect due to the carbonyl group and a +M effect due to the aromatic ring.

C6H5NO2 is most stable due to the strong electron-withdrawing effect of the -NO2 group, which stabilizes the negative charge through resonance.