
Concept explainers
(a) Calculate the percent ionization of a 0.20 M solution of the monoprotic acetylsalic acid (aspirin) for which Ka=3.0 × 10−4. (b) The pH of gastric juice in the stomach of certain individual is 1.00. After a few aspirin tablets have been swallowed, the concentration of acetylsalicylic acid in the stomach is 0.20 M. Calculate the percent ionization of the acid under these conditions. What effect does the nonionized acid has on the membranes lining the stomach? (Hint: See the Chemistry in Action essay “Antacids and the pH Balance in Your Stomach” in Section 15.12.)
(a)

Interpretation:
The percent ionization of the given
Concept Information:
Acid ionization constant
Acids ionize in water. Strong acids ionize completely whereas weak acids ionize to some limited extent.
The degree to which a weak acid ionizes depends on the concentration of the acid and the equilibrium constant for the ionization.
The ionization of a weak acid
The equilibrium expression for the above reaction is given below.
Where,
Percent ionization:
A quantitative measure of the degree of ionization is percent ionization.
For a weak, monoprotic acid
Answer to Problem 15.50QP
The percent ionization of given
Explanation of Solution
From the given concentrations of acetylsalicylic acid solution and its
Then the percent ionization can be calculated from the obtained hydrogen ion concentration as follows,
Construct an equilibrium table and express the equilibrium concentration of each species in terms of
The
Assuming that x is small compared to
The percent ionization can be calculated as follows,
Therefore, the percent ionization of given
(b)

Interpretation:
The percent ionization of acetylsalicylic acid solution under the given condition has to be calculated.
Concept Information:
Acid ionization constant
Acids ionize in water. Strong acids ionize completely whereas weak acids ionize to some limited extent.
The degree to which a weak acid ionizes depends on the concentration of the acid and the equilibrium constant for the ionization.
The ionization of a weak acid
The equilibrium expression for the above reaction is given below.
Where,
Percent ionization:
A quantitative measure of the degree of ionization is percent ionization.
For a weak, monoprotic acid
pH of a solution is the negative of the base
Answer to Problem 15.50QP
The percent ionization of acetylsalicylic acid solution under given condition is
Explanation of Solution
Given,
The pH of gastric juice in the stomach of a certain individual is
The concentration of
According to the Lechatelier’s principle, the position of equilibrium is shifted in the direction of the unionized acid.
Constructing an equilibrium table using the known equilibrium concentration of each species as follows,
The
Assuming that
The percent ionization can be calculated as follows,
The percent ionization of acetylsalicylic acid solution under given condition is
Want to see more full solutions like this?
Chapter 15 Solutions
Loose Leaf for Chemistry
- Hand written equations pleasearrow_forwardHand written equations pleasearrow_forward> each pair of substrates below, choose the one that will react faster in a substitution reaction, assuming that: 1. the rate of substitution doesn't depend on nucleophile concentration and 2. the products are a roughly 50/50 mixture of enantiomers. Substrate A Substrate B Faster Rate X Ś CI (Choose one) (Choose one) CI Br Explanation Check Br (Choose one) © 2025 McGraw Hill LLC. All Rights Farrow_forward
- NMR spectrum of ethyl acetate has signals whose chemical shifts are indicated below. Which hydrogen or set of hydrogens corresponds to the signal at 4.1 ppm? Select the single best answer. The H O HỌC—C—0—CH, CH, 2 A ethyl acetate H NMR: 1.3 ppm, 2.0 ppm, 4.1 ppm Check OA B OC ch B C Save For Later Submit Ass © 2025 McGraw Hill LLC. All Rights Reserved. Terms of Use | Privacy Center |arrow_forwardHow many signals do you expect in the H NMR spectrum for this molecule? Br Br Write the answer below. Also, in each of the drawing areas below is a copy of the molecule, with Hs shown. In each copy, one of the H atoms is colored red. Highlight in red all other H atoms that would contribute to the same signal as the H already highlighted red Note for advanced students: In this question, any multiplet is counted as one signal. 1 Number of signals in the 'H NMR spectrum. For the molecule in the top drawing area, highlight in red any other H atoms that will contribute to the same signal as the H atom already highlighted red. If no other H atoms will contribute, check the box at right. Check For the molecule in the bottom drawing area, highlight in red any other H atoms that will contribute to the same signal as the H atom already highlighted red. If no other H atoms will contribute, check the box at right. O ✓ No additional Hs to color in top molecule ง No additional Hs to color in bottom…arrow_forwardin the kinetics experiment, what were the values calculated? Select all that apply.a) equilibrium constantb) pHc) order of reactiond) rate contstantarrow_forward
- true or false, given that a 20.00 mL sample of NaOH took 24.15 mL of 0.141 M HCI to reach the endpoint in a titration, the concentration of the NaOH is 1.17 M.arrow_forwardin the bromothymol blue experiment, pKa was measured. A closely related compound has a Ka of 2.10 x 10-5. What is the pKa?a) 7.1b) 4.7c) 2.0arrow_forwardcalculate the equilibrium concentration of H2 given that K= 0.017 at a constant temperature for this reaction. The inital concentration of HBr is 0.050 M.2HBr(g) ↔ H2(g) + Br2(g)a) 4.48 x 10-2 M b) 5.17 x 10-3 Mc) 1.03 x 10-2 Md) 1.70 x 10-2 Marrow_forward
- true or falsegiven these two equilibria with their equilibrium constants:H2(g) + CI2(l) ↔ 2HCI(g) K= 0.006 CI2(l) ↔ CI2(g) K= 0.30The equilibrium contstant for the following reaction is 1.8H2(g) + CI2 ↔ 2HCI(g)arrow_forwardI2(g) + CI2(g) ↔ 2ICIK for this reaction is 81.9. Find the equilibrium concentration of I2 if the inital concentration of I2 and CI2 are 0.010 Marrow_forwardtrue or false,the equilibrium constant for this reaction is 0.50.PCI5(g) ↔ PCI3(g) + CI2(g)Based on the above, the equilibrium constant for the following reaction is 0.25.2PCI5(g) ↔. 2PCI3(g) + 2CI2(g)arrow_forward
- Chemistry: Principles and ReactionsChemistryISBN:9781305079373Author:William L. Masterton, Cecile N. HurleyPublisher:Cengage LearningChemistry: The Molecular ScienceChemistryISBN:9781285199047Author:John W. Moore, Conrad L. StanitskiPublisher:Cengage LearningChemistry: Principles and PracticeChemistryISBN:9780534420123Author:Daniel L. Reger, Scott R. Goode, David W. Ball, Edward MercerPublisher:Cengage Learning
- Chemistry & Chemical ReactivityChemistryISBN:9781337399074Author:John C. Kotz, Paul M. Treichel, John Townsend, David TreichelPublisher:Cengage LearningGeneral, Organic, and Biological ChemistryChemistryISBN:9781285853918Author:H. Stephen StokerPublisher:Cengage LearningGeneral Chemistry - Standalone book (MindTap Cour...ChemistryISBN:9781305580343Author:Steven D. Gammon, Ebbing, Darrell Ebbing, Steven D., Darrell; Gammon, Darrell Ebbing; Steven D. Gammon, Darrell D.; Gammon, Ebbing; Steven D. Gammon; DarrellPublisher:Cengage Learning





