Identify the correct order of acidic strength for the indicated hydrogen atoms in the following compounds: (i) (ii) (iii)

Step-by-step solution

The acidic strength of a hydrocarbon depends on the stability of its conjugate base (carbanion) formed after the removal of a proton. In compound (i), triphenylmethane, the conjugate base is the triphenylmethyl anion. Due to steric hindrance between the ortho-hydrogens of the three phenyl rings, the anion cannot achieve a completely planar conformation. This restricts the extent of resonance delocalization of the negative charge, making it the least acidic (pKa 31.5 ). In compound (ii), 9-phenylfluorene, the fluore