How do I compare the acid strengths of the following compounds ?
The correct answer is (C).
In option R and S, R>S because if we extract H from S option from any carbon atom there will be repulsion between negative charge and lone pair of oxygen.andin option R we will extract H from right carbon atom and negative charge will have resonance with ketone.
To check acid strength, see in COOH there is resonance (movement of electrons from one oxygen to other through carbon atom) this is given higher priority
Next alcohol . Clearly there is one option with clear understanding.
Acidity increases with the ease of removing a proton (H+ ion).
In (R) and (S) structures, you should take the effect of O attached to the compound into consideration.
In (S) creating a -ve ion will cause repulsion with the electron cloud of O present in the ring and the ion created by the extraction of a proton. This causes instability of the ion.
in (R), lone pair of an electron will from resonance with the ion so produced. The O atom also shows electronegativity property that pulls the electron cloud from less electronegative parts. Thus, it will further stabilize the compound.