Q.Which of the following is obtained when formic acid is heated with conc. H2SO4?

Formic acid, HCOOH, is structurally unique among carboxylic acids: it carries an aldehyde-type C-H directly on its single carbon alongside the acid group, so, like a true aldehyde, it is easily oxidised and genuinely acts as a REDUCING agent -- a property no other carboxylic acid shares, since none has that extra C-H. It reduces Tollens' reagent to a silver mirror (HCOO- + 2 Ag+ + 3 OH- gives 2 Ag + CO3(2-) + 2 H2O) and reduces Fehling's solution, turning it from blue Cu2+ to red Cu2O (HCOO- + 2 …