Concept explainers
Consider a 0.45 M solution of ascorbic acid,
Calculate the pH of this solution and estimate
Interpretation:
The pH of solution, concentration of
Concept introduction:
The dissociation reaction of a weak acid is represented as follows:
The expression for the acid dissociation constant will be as follows:
Here,
The pH of the solution is calculated as follows:
Here,
Answer to Problem 59QAP
The pH of solution is 2.22, the concentration of
Explanation of Solution
The given acid is ascorbic acid
The initial concentration of
Now, the second ionization reaction is represented as follows:
According to above two ICE tables, the equilibrium concentration of
The expression for dissociation constant is as follows:
Putting the values,
Similarly, the expression for the second ionization constant is as follows:
Putting the values,
Since, the second dissociation constant is very low thus; the value of y can be neglected from the denominator in the equation (2)
Thus, the value of y is
From the ICE table, it is concentration of
Now, in the equation (1),
Calculate the ratio of acid dissociation constant and concentration of acid; if it is less than 0.05 then the value of x from the denominator can be neglected.
The calculated value is less than 0.05 thus,
Or,
Putting the value of y in the above equation,
Or,
Thus, the concentration of
Putting the values,
The concentration of
Putting the values,
The pH of the solution can be calculated as follows:
Putting the values,
Therefore, the pH of solution is 2.22, the concentration of
Therefore, the pH of solution is 2.22, the concentration of
Want to see more full solutions like this?
Chapter 13 Solutions
Chemistry: Principles and Reactions
- Write the ionization equation and the Kb expression for each weak base. CH3NH2 Phosphine, PH3arrow_forwardWrite the reaction and the corresponding Kb equilibrium expression for each of the following substances acting as bases in water. a. aniline, C6H5NH2 b. dimethylamine, (CH3)2NHarrow_forwardProve that Ka3 Kb1 = Kw for phosphoric acid, H3PO4, by adding the chemical equilibrium expressions that corresponds to the third ionization step of the acid in water with the first of the three successive steps of the reaction of phosphate ion, PO43, with water.arrow_forward
- Write the reaction and the corresponding Kb equilibrium expression for each of the following substances acting as bases in water. a. NH3 b. C5H5Narrow_forwardIn each of the following acid-base reactions, identify the Brnsted acid and base on the left and their conjugate partners on the right. (a) C2H5N(aq) + CH3CO2H(aq) C5H5NH+(aq) + CH3CO2(aq) (b) N2H4(aq) + HSO4(aq) N2H5+(aq) + SO42(aq) (c) [Al(H2O)6]3+ (aq) + OH(aq) [Al(H2O)5OH]2+ (aq) + H2O+()arrow_forwardIndicate whether or not the two members of each of the following pairs of substances constitute a conjugate acidbase pair. a. HCl and Cl b. NH4+ and NH3 c. H2CO3 and CO32 d. H2PO4 and HPO42arrow_forward
- Using the diagrams shown in Problem 10-37, which of the four acids is the weakest acid?arrow_forwardWrite the ionization expression and the Kb expression for 0.1 M solutions of the following bases: (a) C2H3O2- (b) C2H5NH2 (c) HC2O4-arrow_forwardWrite an equation to describe the proton transfer that occurs when each of these acids is added to water. (a) HCO3 (b) HCl (c) CH3COOH (d) HCNarrow_forward
- Write an equation that describes the equilibrium that exists when the weak acid benzoic acid (C6H5CO2H) dissolves in water. Identify each of the four species in solution as either Brnsted acids or Brnsted bases. Does the equilibrium favor the products or the reactants? (In acting as an acid, the CO2H group supplies H+ to form H3O+.)arrow_forwardIn each of the following acid-base reactions, identify the Brnsted acid and base on the left and their conjugate partners on the right. (a) HCO2H(aq) + H2O() HCO2(aq) + H3O+(aq) (b) NH3(aq) + H2S(aq) NH4+(aq) + HS(aq) (c) HSO4(aq) + OH(aq) SO42(aq) + H2O+()arrow_forward
- Chemistry: Principles and ReactionsChemistryISBN:9781305079373Author:William L. Masterton, Cecile N. HurleyPublisher:Cengage LearningChemistry & Chemical ReactivityChemistryISBN:9781133949640Author:John C. Kotz, Paul M. Treichel, John Townsend, David TreichelPublisher:Cengage LearningChemistry & Chemical ReactivityChemistryISBN:9781337399074Author:John C. Kotz, Paul M. Treichel, John Townsend, David TreichelPublisher:Cengage Learning
- General, Organic, and Biological ChemistryChemistryISBN:9781285853918Author:H. Stephen StokerPublisher:Cengage LearningChemistry: Principles and PracticeChemistryISBN:9780534420123Author:Daniel L. Reger, Scott R. Goode, David W. Ball, Edward MercerPublisher:Cengage LearningIntroductory Chemistry: A FoundationChemistryISBN:9781337399425Author:Steven S. Zumdahl, Donald J. DeCostePublisher:Cengage Learning