a.
To determine: In which direction the given reaction will proceed when the pH of a solution begins to fall.
Introduction: At the equilibrium, the product of the H+ and OH- concentration of an aqueous solution is 10-14. The pH is the negative of base 10 logarithm of H+ concentration (moles per liter). However, pOH is the negative of the base 10 logarithm of hydroxide ion (OH-) concentration.
b.
To determine: In which direction the given reaction will proceed when the pH of a solution rises above normal level.
Introduction: The pH of a solution is denoted as the negative logarithm of the hydrogen ion concentration of that solution. The pH in a solution decreases as H+ ion concentration increases in the solution. The pH of a neutral aqueous solution is 7, if it exceeds 7 it is a base, if it is below 7 it is an acid. A buffer is simply a mixture that contains a weak acid and its corresponding base. It neutralizes the solution by adding acids and bases. It reacts with any added base or acid to maintain pH.
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Study Guide for Campbell Biology
- Using chemical equations, explain how bicarbonate ion and carbonic acid function as a buffer pair.arrow_forwardConsider a buffer solution of acetate. The volume is 500 ml, the concentration is 200 mM, and the pH is 5.0. a. How many total moles of acetate plus acetic acid are present in the solution? Express answer as x.y with one digit before and one after the decimal place. b. What is the ratio of acetate ions (Ac-) to acetic acid ions (HAc) in the buffer solution (pH 5.0) if the pka is 4.76? Express the answer as x.yz with one digit before and two after the decimal place. c. How many moles of acetate are present in the solution? Express your answer to one decimal place. d. How many moles of acetic acid are present in the solution? Express your answer to one decimal place.arrow_forwardWrite the equations for reaction of this buffer with a small amount of HNO3 and with a small amount of NaOH.arrow_forward
- 20 mL solution is 2 M NaOH. If 0.5 M HCl is to be added to this solution, calculate the pH of the resulting solution: A. when 10 mL of the 0.5 M HCl is added to the original solution of the base (initial pH). B. When 50 mL H20 is added to the original solution of the base.arrow_forwardThis is all part of one question. It goes together. (I wrote D and E that were cut off from the picture.) Please help me solve this since it all follows a line.D. At which pH value does the amino group of amino acid have the best buffering capacity?9.009.691.536.013.0010.5E. What is the pI (isoelectric point)?pI=arrow_forwardDefine the following:- pH- Buffer- pKaarrow_forward
- Angiotensin Converting Enzyme (ACE) is the target of ACE inhibitors such as captopril that are used therapeutically to control blood pressure. The enzyme ACE converts angiotensin I to angiotensin II. Angiotensin II is an octapeptide with the sequence Asp-Arg-Val-Tyr-Ile-His-Pro-Phe. What will its net charge be at pH 7? A) -2 B) -1 O C) O D) +1 E) +2arrow_forwardYou have been provided with stock solutions of: stock A: 0.06 M sodium pyrophosphate buffer pH 8.5 stock B: 3 M ethanol stock C: 0.015 M NAD+ stock D: milli Q water Determine the volume you will need of each solution to prepare a buffer of with a final volume of 60 mL containing 10 mM sodium pyrophosphate pH 8.5, 100 mM ethanol, 1 mM NAD+. i.e. volume of stock A = _________mL volume of stock B = _________mL volume of stock C = _________mL volume of stock D = _________mL Show your calculations to arrive at your answers.arrow_forwardDraw titration curve for compound X when NaOH equivalence(s) is/are added. Indicate the buffering region(s) with a box.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_forwardthe pH of a solution is decreased from 9 to 8, it means that the A) concentration of H+ has decreased to one-tenth (1/10) what it was at pH 9. B) concentration of H+ has increased 10-fold (10X) compared to what it was at C) concentration of OH- has increased 10-fold (10X) compared to what it was at D) concentration of OH- has decreased to one-tenth (1/10) what it was at pH 9. E) Both B and D are correct. parrow_forwardBased on our pka's table, pKa1 of -COOH group of Cys = 1.71 pKa2 of -NH2 group of Cys = 10.78 pKa3 of side chain group of Cys = 8.33 If pKa is different, will the buffer change??arrow_forward