Which metal in following compounds is not present in fractional oxidation state?

Which among the following is NOT dicarboxylic acid?

Identify the substrate ' X ' in the following reaction.

$$ \mathrm{X}+\underset{\text { (air) }}{\mathrm{O}_2} \xrightarrow[\text { ii) dil HCl } \Delta]{\text { i) Co-naphenate } 423 \mathrm{~K}} \text { Phenol }+ \text { Acetone } $$

Identify the monomers use to prepare glyptal.