Interpretation:
For the given reaction under given conditions the balanced equation, conjugate acid-base pair and the direction of equilibrium should be identified.
Concept introduction:
: If a species loses a proton then it is considered as
Strong Acids: Acids that dissociates into ions completely which results in easy donation of protons are considered as strong acids. Strong acid forms weaker conjugated base.
Weak Acids: Acids that do not easily dissociate into ions completely which has difficulty in proton donation are considered as weak acids. Weak acid forms stronger conjugated base
: If a species receives one proton, then it is considered as
Strong Base: Bases that has strong attraction towards protons and accepts readily. Strong base forms weaker conjugated acid.
Weak Base: Bases that has little affinity towards protons. Weak base forms stronger conjugated acid.
If a base receives one proton, then the formed species is a conjugate acid whereas an acid lose one proton, then the formed species is a conjugated base.
Equilibrium: A state of a
The principle says that when a disturbance is given to equilibrium of a chemical reaction, the equilibrium will respond by shifting to the direction at which the effect of disturbance is nullified
Balanced Chemical Reaction: On accordance with law of conservation of mass, for any chemical reaction, total masses of reactants and products must be equal.
Want to see the full answer?
Check out a sample textbook solutionChapter 10 Solutions
Fundamentals of General, Organic, and Biological Chemistry (8th Edition)
- Sketch out the titration curve below and the structure(s) of the major ionic form(s) of glutamic acid that exist in solution at the noted parts of the titration curve. Refer to the fully protonated glutamic acid and the pKaarrow_forwardAn enzyme uses a lysine and a histidine as general acid-base catalytic residues. In one direction of the reaction, the lysine and histidine residues are typically protonated (~NH3*, ~Im), but in the other direction of the reaction, the two residues are "reverse protonated" (~NH2, ~Hlm*) (see below scheme). A pH profile of the reaction at various pH values yielded estimates of 7.57 and 9.30 for the macroscopic ionization constants pk,' and pK2, respectively. A separate set of experiments with site-speciffic variants of the enzyme yielded an estimate of 8.78 for the microscopic ionization constant pKp. Given this information, what is the value of the microscopic ionization constant pKA? Report your answer to the nearest hundredth. Lys-NH3* His-HIm" KB H KA H* Lys-NH2 Lys-NH3* His-HIm" His-Im Kc H* Kp Lys-NH2 His-Imarrow_forwardGive the equation for the complete titration of aspartic acid with a base, NaOH. At what pH, can you use aspartate solution a buffer?arrow_forward
- Identify the acid and conjugate base in each reaction. Calculate the pKa for each acid. List them in order from the strongest to weakest acid. The acid-ionization constants, Ka, at 25°C are listed for each. a. HC2H3O2 + H2O ↔ H3O+ + C2H3O2-acetic acid, KA = 1.7 x 10-5 b. HC7H5O2 + H2O H₂O+ + C7H5O2-benzoic acid, KA= 6.3 x 10-5 c. HC6H4NO2 + H2O ↔ H3O++ C6H4NO2-nicotinic acid, KA = 1.4 x 10-5arrow_forwardGlutamic acid (1one of the 20 amino acids) has a side- chain carboxyl group (COOH, pKa = 4.3) as shown in Figures 4.7 and 4.8 a. Write the chemical equation for the dissociation of the side chain COOH. Label the weak acid and the conjugate base. b. The Henderson-Hasselbalch Equation (shown below) can be used to determine the ionization status of a weak acid: pH = pKa + log [base] Use the Henderson Hasselbalch equation to determine whether the glutamic acid side chain [acid] • carboxyl group is protonated or deprotonated at physiological pH.arrow_forwardThe ionization of p-nitrophenol is shown below (pKa = 7.0): a. Identify the weak acid and conjugate base. b. At pH 7, what are the relative concentrations of ionized and un-ionized p-nitrophenol? c. If enough concentrated hydrochloric acid is added to a solution of p-nitrophenol to lower the pH from 7 to 5, what will happen to the relative concentrations of the ionized and un-ionized forms? d. Ionized p-nitrophenol has a yellow color, while the un-ionized form is colorless. The yellow color can be measured using a spectrophotometer at 400nm. In order to determine the total amount of p-nitrophenol in a solution, would you perform the spectrophotometer reading at an acidic or basic pH? Clearly explain why? e. A solution of p-nitrophenol at pH 7.95 was found to have an A400 of 0.255 . What is the total concentration (in µM) of p-nitrophenol (ionized plus un-ionized) in the solution? The molar extinction coefficient of p-nitrophenol is 18,500 M-1cm-1 and the pKa is 7.arrow_forward
- Potentiometric titration curve is given below, which is obtained during the potentiometric titration between strong base KOH (0.2 M) with strong acid HI, label the point in the curve from the following options. If more than one points are present than write as x, y(means separate by using comma) a)The point where pH is because of excess OH - ions. b) The point where pH is only because of HI in water. c)The point where [HI]= [I] in water. d)The point where pH=pka e) The point where all HI is neutralized. f) The point where pH corresponds to solution of [I- ] in water. 14 13 12 11 10 9 pH 6. TITIT TITarrow_forwardThe enzyme urease is widely used for determining urea concentration in blood. The Michaelis constant for urease at room temperature is 2.0 mM and k2 = 2.8 × 104 s-1 at pH = 7.5. Based on the kinetic experiment, when 0.34 mM urease was used, the initial rate of the reaction was determined to be 3.49 M/sec. What is the concentration of urea in blood in unit of mM? Please keep your answer to two decimal place. Please convert all concentration unit to mM in calculation.arrow_forwardThe following amino acid is dissolved in solution at pH 7.4. HC H' + CH CH₂ H/ H+ HC a. Which amino acid is this? (all lower case) N- H CH CH₂ b. What is the pKa of its ionizable side chain? (Use the value from the textbook.) c. What is the ratio of the uncharged to the charged form at pH 7.4? (write answer as number with one decimal place, ex 2.5 or 0.2 or 50.0 with an implicit "to 1")arrow_forward
- Glycine hydrochloride (Cl− H3N+CH2COOH) is a diprotic acid that contains a carboxylic acid group and an ammonium group and is therefore called an amino acid. It is often used in biochemical buffers. Solve, In analogy with Figure , sketch the titration curve of this diprotic acid.arrow_forwardA monoprotic weak acid, HA, dissociates in water according to the reaction HA(aq) = H+ (aq) + A¯(aq) The equilibrium concentrations of the reactants and products are [HA] = 0.220 M, [H+] = 3.00 × 10−4 M, and [A¯] = 3.00 × 10−4 M. Calculate the value of pKa for the acid HA. pKa =arrow_forwardIn many biochemical reactions which involves the formation of an enolate intermediate, the carbonyl oxygen of the substrate is coordinated to a divalent metal ion (usually zinc or magnesium) in the active site. Explain with structural drawings, how this ion-dipole interactions affect the acidity of the a-protons?arrow_forward
- BiochemistryBiochemistryISBN:9781319114671Author:Lubert Stryer, Jeremy M. Berg, John L. Tymoczko, Gregory J. Gatto Jr.Publisher:W. H. FreemanLehninger Principles of BiochemistryBiochemistryISBN:9781464126116Author:David L. Nelson, Michael M. CoxPublisher:W. H. FreemanFundamentals of Biochemistry: Life at the Molecul...BiochemistryISBN:9781118918401Author:Donald Voet, Judith G. Voet, Charlotte W. PrattPublisher:WILEY
- BiochemistryBiochemistryISBN:9781305961135Author:Mary K. Campbell, Shawn O. Farrell, Owen M. McDougalPublisher:Cengage LearningBiochemistryBiochemistryISBN:9781305577206Author:Reginald H. Garrett, Charles M. GrishamPublisher:Cengage LearningFundamentals of General, Organic, and Biological ...BiochemistryISBN:9780134015187Author:John E. McMurry, David S. Ballantine, Carl A. Hoeger, Virginia E. PetersonPublisher:PEARSON