An aqueous solution of acetic acid solution [CH3CO2H(aq)] has a pH of 3.25. Which of these substances raises the pH of the solution upon addition?

Question

BlackTom AI · Accepted Answer

To determine which substance raises the pH of an acidic solution, we need to consider how each additive affects acidity and the overall proton balance in solution.
Option 1: HCO2H (formic acid) is a weak acid. Adding more of a weak acid to an acidic solution tends to increase the concentration of H+, unless it also shifts equilibrium in a way that reduces H+, but for a standalone addition, it would typically not raise pH and may even lower it depending on buffering, so this choice is unlikely to raise pH.
Option 2: CH3CO2Na (sodium acetate) is a salt containing the conjugate base of acetic acid (CH3CO2–). When dissolved, it hydrolyzes to form acetate ions that can accept protons (acting as a weak base) and water, producing OH– in the process. In an acetic acid solution, adding acetate shifts the equilibrium toward consumption of H+ to form acetic acid, thereby increasing pH. This is the classic buffer and base-augmenting behavior.
Option 3: HCl (hydrochloric acid) is a strong acid. Adding a strong acid to an already acidic solution will increase the concentration of H+, thus lowering the pH, not raising it.
Option 4: NaCl (sodium chloride) is a neutral salt from a strong acid and a strong base. In pure water it has negligible effect on pH; in an acidic solution, it does not provide a conjugate base or acid that would neutralize H+ significantly, so its effect on pH would be minimal or neutral rather than raising it.
Overall, the only additive that can raise the pH of an acidic acetic acid solution by supplying conjugate base that consumes protons is CH3CO2Na, due to its basic acetate ion component capable of buffering and reducing free H+.

An aqueous solution of acetic acid solution [CH3CO2H(aq)] has a pH of 3.25. Which of these substances raises the pH of the solution upon addition?单项选择题

类似问题

In the reaction, HClO3 + N2H4 ⇌ ClO3– + N2H5+, which one of the sets below lists both of the acid species involved in the equilibrium?

Which of the following statements correctly explains the dissociation of ethanoic acid in water?

If Kb for NH₃ is 1.8 × 10⁻⁵ at 25 0C, what is the pKa of its conjugate acid (NH₄⁺)?

In the reaction, HClO3 + N2H4 ⇌ ClO3– + N2H5+, which one of the sets below lists both of the acid species involved in the equilibrium?

Find the pH of a 0.350 M aqueous benzoic acid solution. For benzoic acid, Ka = 6.5 × 10–5.

What is the pH of a solution of Na2HPO3? (The pKa values for H3PO3 are: pKa1 = 2.15, pKa2 = 7.20, pKa3 = 12.35)

Which of the following trees corresponds to a potential parse of the ambiguous sentence below, with correct syntactic categories? Some diagnostics are provided.

Which of the following sentences contain two non-finite verbs? Select all that apply.

更多留学生实用工具

智能学习助手

风格化写作助手

论文查重助手

文献引用助手

课堂转译助手

课堂笔记助手

Quiz搜索助手

学校历年真题

智能刷题助手

智能匹配练习

希望你的学习变得更简单