A 0.025 M solution of a weak acid has a percent ionization of 3.2%. What is the Ka of the weak acid?

Question

BlackTom AI · Accepted Answer

A 0.025 M solution of a weak acid has a percent ionization of 3.2%. To find Ka, relate the ionization to the acid’s dissociation equilibrium HA ⇌ H+ + A−.

First, convert percent ionization to a fraction: 3.2% = 0.032. The fraction ionized times the initial concentration gives the hydrogen ion concentration at equilibrium: [H+] = αC0 = 0.032 × 0.025 M = 0.0008 M.

Next, determine the concentration of the undissociated acid at equilibrium: [HA] = C0 − [H+] = 0.025 − 0.0008 = 0.0242 M.

Now apply the expression for the acid dissociation constant: Ka = [H+][A−] / [HA]. Since [H+] = [A−] = 0.0008 M, Ka = (0.0008)^2 / 0.0242.

Compute the numerator: (0.0008)^2 = 6.4 × 10^−7. Divide by 0.0242 to obtain Ka ≈ 2.64 × 10^−5.

Therefore, the calculated Ka is 2.64 × 10^−5. If you round to two significant figures, it remains approximately 2.6 × 10^−5; to three significant figures, 2.64 × 10^−5. This approach relies on the definition of percent ionization and the standard Ka expression for a monoprotic weak acid.

A 0.025 M solution of a weak acid has a percent ionization of 3.2%. What is the Ka of the weak acid?单项选择题

类似问题

Write an expression for the acid ionization constant (Ka) for the dissociation of the following weak acid H2CO3.

A 0.10 M solution of a weak acid, HX, is 0.059% ionized. Evaluate Ka for the acid.

The pH of a solution of a 0.15 M solution of HOCl is 4.14. What is the Ka for HOCl?

For the dissociation of a very weak acid, HA, in water

The larger the value of Ka

The pH of a 0.800 M aqueous solution of a weak acid is 1.99. What is the value of Ka for this acid?

Based on the following titration curve, what is the Ka for this weak acid?

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

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