See image — GOC and Organic Chemistry Basics Chemistry Question

💡 Solution & Explanation

# Solution To identify which reaction goes nearly to completion, we need to analyze the driving forces for each reaction: ## Analysis of Each Option **(A) Phenol + $NaHCO_3$:** Phenol ($K_a \approx 10^{-10}$) is a very weak acid. $NaHCO_3$ is a weak base. Since phenol is weaker than carbonic acid, this reaction does **not** favor products significantly. **(B) Acetylene + NaOH:** Acetylene ($K_a \approx 10^{-25}$) is an extremely weak acid. NaOH cannot deprotonate it effectively. This reaction is **unfavorable**. **(C) Diketene + NaOH:** This is an elimination reaction forming an alkene, but it's **reversible and doesn't go to completion** because the product can undergo reverse reactions. **(D) Diisopropylamine + n-Butyllithium:** $$[(CH_3)_2CH]_2NH + CH_3CH_2CH_2CH_2Li \rightarrow [(CH_3)_2CH]_2NLi + CH_3CH_2CH_2CH_3$$ **Why this goes to completion:** - **Strong acid-base reaction:** Diisopropylamine ($K_a \approx 10^{-35}$ for conjugate acid) is much stronger than butane ($K_a \approx 10^{-50}$) - **Irreversible:** Butane (alkane) cannot donate a proton back to the lithium amide anion - **Thermodynamically favorable:** Large equilibrium constant heavily favors product formation - **Organometallic strength:** Alkyllithium reagents are extremely strong bases, ensuring complete deprotonation **Answer: (D)** — This reaction is a strong acid-weak acid proton transfer that goes essentially to completion because the conjugate base of butane is an extremely poor proton donor.