Concept explainers
A 25.0-mL solution of 0.100 M
Interpretation:
The pH values of the solution after the addition of different volumes of
Concept introduction:
Acid–base titration is a technique used to analyze the unknown concentration of the acid or the base through the known concentration of the acid and base.
The equivalence point is the point in the acid–base titration of the chemical reaction where the number of moles of the titrant and the unknown concentration of the analyte are equal. It is used to identify the unknown concentration of the analyte.
The value of pH expresses the acidity or alkalinity of a solution on a logarithmic scale.
When the value of pH is equal to
The formula to calculate the pH of a solution is:
pOH is a measure of the basicity of a solution, which depends on the concentration of hydroxide ions and the temperature of the solution.
The formula to calculate the pOH of a solution is:
The relation between pH and pOH is as:
A base dissociation constant, Kb, (also known base-ionization constant) is a quantitative measure of the strength of an base in solution.
The ionization of a weak base can be represented by the equation:
Where B is weak base and
The base ionization constant for a weak base is:
Where
An acid dissociation constant, Ka, (also known as acidity constant, or acid-ionization constant) is a quantitative measure of the strength of an acid in solution
The dissociation of a weak acid in an aqueous solution:
The acid ionization constant for a weak acid is:
The number of moles of compound initially present in the solution is calculated as:
The molarity of a compound is given by the expression as:
The pH of the buffer solution by the Henderson–Hasselbalch equation can be calculated as:
Answer to Problem 35QP
Solution:
a)
b)
c)
d)
e)
Explanation of Solution
Given information: The concentration of
Explanation:
a)
The neutralization reaction between
From the above equation, 1 mole of
Let
The initial ionization change table for the ionization of
The equilibrium expression for the reaction is represented as follows:
Here,
Substitutes the values of
The value of
Concentration of
The value of
Substitute the value of
Hence, the
Explanation:
b)
The number of moles of
Substitute the values of the concentration and the volume of
The number of moles of
Substitute the values of the concentration and the volume of
On mixing the two solutions, the molarity of the solution changes, but the number of moles will remain the same.
The changes in the number of moles of
Determine the pH of the buffer solution by the Henderson–Hasselbalch equation. This is a basic buffer.
The pH of the buffer is calculated as follows:
Hence, the
Explanation:
c)
The number of moles of
Substitute the values of the concentration and the volume of
The number of moles of
Substitute the values of the concentration and the volume of
On mixing the two solutions, the molarity of the solution changes, but the number of moles will remain the same.
The changes in the number of moles of
Determine the pH of the buffer solution by the Henderson–Hasselbalch equation.
The pH of the buffer is calculated as follows:
Hence, the
Explanation:
d)
The number of moles of
Substitute the values of the concentration and the volume of
The number of moles of
Substitute the values of the concentration and the volume of
On mixing the two solutions, the molarity of the solution changes, but the number of moles will remain the same.
The changes in the number of moles of
At this stage, an equivalence point of the titration is reached.
The molarity of
Substitute the values of the number of moles and the volume of
Let
The initial concentration change for the ionization of
The equilibrium expression for the reaction is written as follows:
Here,
Substitute the values of
The value of x is very small as compared to
Concentration of
The
Substitute the value of
The value of
Hence, the
e)
Given information: The concentration of
Explanation:
The number of moles of
Substitute the values of the concentration and the volume of
The number of moles of
Substitute the values of the concentration and the volume of
On mixing the two solutions, the molarity of the solution changes, but the number of moles will remain the same.
The changes in the number of moles of
The molarity of
Substitute the values of the number of moles and the volume
The concentration of
The
Substitute the value of
The value of
Substitute the value of
Hence, the
Want to see more full solutions like this?
Chapter 17 Solutions
CHEMISTRY(LOOSELEAF W/CODE)- CUSTOM
- Calculate the mass of sodium acetate, NaCH3COO, you should add to 500. mL of a 0.150-M solution of acetic acid, CH3COOH, to buffer a solution at a pH of 4.57.arrow_forwardKa for formic acid is 1.7 104 at 25C. A buffer is made by mixing 529 mL of 0.465 M formic acid, HCHO2, and 494 mL of 0.524 M sodium formate, NaCHO2. Calculate the pH of this solution at 25C after 110 mL of 0.152 M HCl has been added to this buffer.arrow_forwardSketch a titration curve for the titration of potassium hydroxide with HCl, both 0.100 M. Identify three regions in which a particular chemical species or system dominates the acid-base equilibria.arrow_forward
- What is the pH of the solution obtained by titrating 1.30 g of sodium hydrogen sulfate, NaHSO4, dissolved in 50.0 mL of water with 0.175 M sodium hydroxide until the equivalence point is reached? Assume that any volume change due to adding the sodium hydrogen sulfate or to mixing the solutions is negligible.arrow_forwardA solution is prepared by dissolving 0.350 g of benzoic acid, HC7H5O2, in water to make 100.0 mL of solution. A 30.00-mL sample of the solution is titrated with 0.272 M KOH. Calculate the pH of the solution (a) before titration. (b) halfway to the equivalence point. (c) at the equivalence point.arrow_forwardThe pH of 0.10 M CH3NH2 (methylamine) is 11.8. When the chloride salt of methylamine, CH3NH3Cl, is added to this solution, does the pH increase or decrease? Explain, using Le Chteliers principle and the common-ion effect.arrow_forward
- A buffer is prepared by mixing 525 mL of 0.50 M formic acid, HCHO2, and 475 mL of 0.50 M sodium formate, NaCHO2. Calculate the pH. What would be the pH of 85 mL of the buffer to which 8.6 mL of 0.15 M hydrochloric acid had been added?arrow_forwardWhich of the acid-base indicators discussed in this chapter would be suitable for the titration of (a) HNO3 with KOH. (b) KOH with acetic acid. (c) HCl with NH3. (d) KOH with HNO2. Explain your answers.arrow_forwardWhen 40.00 mL of a weak monoprotic acid solution is titrated with 0.100-M NaOH, the equivalence point is reached when 35.00 mL base has been added. After 20.00 mL NaOH solution has been added, the titration mixture has a pH of 5.75. Calculate the ionization constant of the acid.arrow_forward
- Sodium benzoate, NaC7H5O2, is used as a preservative in foods. Consider a 50.0-mL sample of 0.250 M NaC7H5O2 being titrated by 0.200 M HBr. Calculate the pH of the solution: a when no HBr has been added; b after the addition of 50.0 mL of the HBr solution; c at the equivalence point; d after the addition of 75.00 mL of the HBr solution. The Kb value for the benzoate ion is 1.6 1010.arrow_forward2. If an acetic acid/sodium acetate buffer solution is prepared from 100. mL of 0.10 M acetic acid what volume of 0.10 M sodium acetate must be added to have a pH of 4.00? 100. mL 50. mL 36 mL 18 mLarrow_forwardA sodium hydrogen carbonate-sodium carbonate buffer is to be prepared with a pH of 9.40. (a) What must the [ HCO3 ]/[ CO32 ]ratio be? (b) How many moles of sodium hydrogen carbonate must be added to a liter of 0.225 M Na2CO3 to give this pH? (c) How many grams of sodium carbonate must be added to 475 mL of 0.336 M NaHCO3 to give this pH? (Assume no volume change.) (d) What volume of 0.200 M NaHCO3 must be added to 735 mL of a 0.139 M solution of Na2CO3 to give this pH? (Assume that volumes are additive.)arrow_forward
- Chemistry: An Atoms First ApproachChemistryISBN:9781305079243Author:Steven S. Zumdahl, Susan A. ZumdahlPublisher:Cengage LearningChemistryChemistryISBN:9781305957404Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCostePublisher:Cengage Learning
- General 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 LearningChemistry: Principles and ReactionsChemistryISBN:9781305079373Author:William L. Masterton, Cecile N. HurleyPublisher:Cengage LearningChemistry & Chemical ReactivityChemistryISBN:9781337399074Author:John C. Kotz, Paul M. Treichel, John Townsend, David TreichelPublisher:Cengage Learning