See image — GOC and Organic Chemistry Basics Chemistry Question

💡 Solution & Explanation

Concept: For a base to convert an alcohol (R-OH) into its alkoxide (R-ONa) in a reaction that goes to completion, the conjugate acid of the base must be a weaker acid than the alcohol. In other words, the base must be stronger than the alkoxide (the conjugate base of the alcohol). The pKa of (CH3)3COH (tert-butanol) is approximately 19. For a reaction to go to completion, the base used must have a conjugate acid with a pKa significantly higher than 19 (i.e., the base must be stronger than the tert-butoxide ion). Evaluating each option: (a) NaNH2: The conjugate acid is NH3, with pKa ≈ 38. Since 38 >> 19, NaNH2 is a strong enough base and the reaction goes to completion. ✓ (b) CH3CH2Na (sodium ethide / ethyl sodium, i.e., the carbanion of ethane): The conjugate acid is ethane (CH3CH3), with pKa ≈ 50. Since 50 >> 19, this base is more than strong enough and the reaction goes to completion. ✓ (c) NaOH: The conjugate acid is water, with pKa ≈ 15.7. Since 15.7 < 19, NaOH is NOT strong enough to deprotonate tert-butanol to completion; the equilibrium would favor the alcohol side. ✗ (d) CH3CO2Na (sodium acetate): The conjugate acid is acetic acid, with pKa ≈ 4.75. Since 4.75 << 19, sodium acetate is far too weak a base. ✗ Both (a) NaNH2 and (b) CH3CH2Na are strong enough to convert (CH3)3COH into (CH3)3CONa in a reaction that goes to completion, making more than one of the above correct. Therefore, the correct answer is E.