Which of the following bases are strong enough to cause...

Which of the following bases are strong enough to cause essentially complete deprotonation of methanol? The $\mathrm{p} K_{\mathrm{a}}$ of the conjugate acid is given in parentheses. (a) $\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{Li}(50)$; (b) $\mathrm{CH}_{3} \mathrm{CO}_{2} \mathrm{Na}(4.7)$; (c) LiN[CH(CH $\left._{3}\right)_{2} /_{2}$ (LDA, 40 ); (d) $\mathrm{KH}(38) ;$ (e) $\mathrm{CH}_{3} \mathrm{SNa}(10)$.

Which of the following bases are strong enough to cause essentially complete deprotonation of methanol? The $\mathrm{p} K_{\mathrm{a}}$ of the conjugate acid is given in parentheses.
(a) $\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{Li}(50)$;
(b) $\mathrm{CH}_{3} \mathrm{CO}_{2} \mathrm{Na}(4.7)$;
(c) LiN[CH(CH $\left._{3}\right)_{2} /_{2}$ (LDA, 40 );
(d) $\mathrm{KH}(38) ;$ (e) $\mathrm{CH}_{3} \mathrm{SNa}(10)$.

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Key Concepts

Acid-Base Equilibrium

This concept revolves around the reversible reaction between acids and bases. In acid-base reactions, the relative strength of acids and bases is determined by their propensity to donate or accept protons. The position of the equilibrium in such reactions is heavily influenced by the differences in the acid strengths (often quantified by pKa values) of the species involved.

pKa Values

The pKa value is a logarithmic measure of an acid’s strength, where a lower pKa indicates a stronger acid (more readily donates a proton) while a higher pKa indicates a weaker acid. In the context of deprotonation reactions, a base is typically effective if its conjugate acid has a pKa significantly higher than that of the acid being deprotonated, ensuring that the equilibrium favors the formation of the deprotonated species.

Conjugate Acid-Base Relationship

Every acid-base reaction involves a conjugate acid and a conjugate base. The strength of a base is inversely related to the acidity of its conjugate acid. If the conjugate acid of a base has a very high pKa, the base is strong because its conjugate acid is very weak, making the deprotonation reaction of a given substrate more likely to proceed to completion.

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