Log out Go to App
Go to App

Learning Materials

Features

Discover

Chapter 16: Problem 117

Propionic acid, \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{COOH},\) is \(0.42 \%\) ionized in \(0.80 \mathrm{M}\) solution. The \(K_{\mathrm{a}}\) for this acid is (a) \(1.42 \times 10^{-5}\) (b) \(1.42 \times 10^{-7} ;\) (c) \(1.77 \times 10^{-5} ;\) (d) \(6.15 \times 10^{4}\) (e) none of these.

Short Answer

Expert verified
(e) None of these

Step by step solution

01

Understanding Ionization percentage and Ka

First, it is important to know that \([H^+]\), \(C_i\) (initial concentration of the acid), and \(K_a\) are all related. Since the acid is weakly ionized, the mathematical relationship is approximately \(K_a=[H^+]/C_i\) due to the equilibrium of the ionization.
02

Calculating the concentration of H+

Because we know the ionization percentage (0.42%) and the initial concentration (\(C_i\)=0.80M), the concentration of \(H^+\) in the solution can be found as \(C_i\) multiplied by the percent ionization in decimal form. This gives: \([H+]=0.80 * 0.0042 = 0.00336\, M\). This is the concentration of \(H^+\) which ionized from the acid.
03

Calculating Ka

Now use the definition of \(K_a\), \(K_a= [H+]/C_i\), to find the value of Ka. This gives: \(K_a=0.00336/0.80 = 4.20 x 10^-5\).
04

Matching the Ka value

Comparing the calculated Ka to the options given, we see that none of the provided options perfectly match the calculated result. Therefore, the right answer is 'none of these'.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Start your free trial

Over 30 million students worldwide already upgrade their learning with Vaia!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Predict whether a solution of each of the following salts is acidic, basic, or pH neutral: (a) KCl; (b) KF; (c) \(\mathrm{NaNO}_{3} ;\) (d) \(\mathrm{Ca}(\mathrm{OCl})_{2} ;\) (e) \(\mathrm{NH}_{4} \mathrm{NO}_{2}\)

A saturated aqueous solution of \(\mathrm{Ca}(\mathrm{OH})_{2}\) has a pH of 12.35. What is the solubility of \(\mathrm{Ca}(\mathrm{OH})_{2}\), expressed in milligrams per 100 mL of solution?

Each of the following is a Lewis acid-base reaction. Which reactant is the acid, and which is the base? Explain. (a) \(\mathrm{SO}_{3}+\mathrm{H}_{2} \mathrm{O} \longrightarrow \mathrm{H}_{2} \mathrm{SO}_{4}\) (b) \(\operatorname{Zn}(\mathrm{OH})_{2}(\mathrm{s})+2 \mathrm{OH}^{-}(\mathrm{aq}) \longrightarrow\left[\mathrm{Zn}(\mathrm{OH})_{4}\right]^{2-}(\mathrm{aq})\)

For each reaction draw a Lewis structure for each species and indicate which is the acid and which is the base: (a) \(\mathrm{CO}_{2}+\mathrm{H}_{2} \mathrm{O} \longrightarrow \mathrm{H}_{2} \mathrm{CO}_{3}\) (b) \(\mathrm{H}_{2} \mathrm{O}+\mathrm{BF}_{3} \longrightarrow \mathrm{H}_{2} \mathrm{OBF}_{3}\) (c) \(\mathrm{O}^{2-}+\mathrm{H}_{2} \mathrm{O} \longrightarrow 2 \mathrm{OH}^{-}\) (d) \(\mathrm{S}^{2-}+\mathrm{SO}_{3} \longrightarrow \mathrm{S}_{2} \mathrm{O}_{3}^{2-}\)

What is the pH of the solution obtained by mixing \(24.80 \mathrm{mL}\) of \(0.248 \mathrm{M} \mathrm{HNO}_{3}\) and \(15.40 \mathrm{mL}\) of \(0.394 \mathrm{M}\) \(\space\) \(KOH?\)
See all solutions

Recommended explanations on Chemistry Textbooks

Nuclear Chemistry

Read Explanation

Organic Chemistry

Read Explanation

Kinetics

Read Explanation

Ionic and Molecular Compounds

Read Explanation

Chemical Reactions

Read Explanation

The Earths Atmosphere

Read Explanation
View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.

Sign-up for free