Answer:
Example:
For the sulfuric acid
H2SO4 ---------> H+ + HSO4- here Ka1 = 1.0 *10^3
HSO4- ---------> H+ + SO42- : Ka2 = 1.2*10^-2
Here the successive Ka values are reducing.
17. With polyprotic acids multiple K values are witnessed with each step in their dissociation. E...
17. With polyprotic acids multiple K,values are witnessed with each step in their dissociation. Examine a few examples. What do the successive K, values imply about each successive dissociation?
16. Find the concentration of [H] in 1,0 M sodium dihydrogen phosphate solution given that the first K-7.5x10, second K,=6.2x10 and third K.-4,8x1013 17. With polyprotic acids multiple K, values are witnessed with each step in their dissociation. Examine a few examples. What do the successive K, values imply about cach successive dissociation?
Polyprotic acids contain more than one dissociable proton. Each dissociation step has its own acid-dissociation constant, Ka1, Ka2, etc. For example, a diprotic acid H2A reacts as follows: H2A(aq)+H2O(l)⇌H3O+(aq)+HA−(aq) Ka1=[H3O+][HA−][H2A] HA−(aq)+H2O(l)⇌H3O+(aq)+A2−(aq) Ka2=[H3O+][A2−][HA−] In general, Ka2 = [A2−] for a solution of a weak diprotic acid because [H3O+]≈[HA−]. Many household cleaning products contain oxalic acid, H2C2O4, a diprotic acid with the following dissociation constants: Ka1=5.9×10−2, Ka2=6.4×10−5 Part A) Calculate the equilibrium concentration of H3O+ in a 0.20 M solution of oxalic...
Writing polyprotic acid and base reactions: 1. Write all the dissociations for the three polyprotic acids: H_2CO_3, H_3AsO_4, H_3PO_4. Match the appropriate Ka1, Ka2, Ka3 values to the dissociation reaction. 2. Identify all the species in each of the reactions as either an acid, a base, or amphoteric. Imagine putting NaH_2AsO_4 in solution. This is a salt. Describe, using chemical equation, exactly what happens? First write the dissociation reaction of the salt. Then identify the pH active species, and then...
Learn Ch 17: Acids and Bases det aptir QUESTION ANSWER miy aptiv 2.52 ats Weak acids and bases are those that do not completely dissociate in water. The dissociation of the acid or base is an equilibrium process and has a corresponding equilibrium constant. K is the equilibrium constant for the dissociation of a weak acid and K is the equilibrium constant for the dissociation of a weak bas. 6.33 ООООО 7.67 What is the pH of a 0.145 M...
Part 3: Working with the Titration Curve for a Polyprotic Acid and Strong Base Consider carbonic acid, H.CO, (which is polyprotic) - a) Write the multi-step dissociation equilibrium for this acid in water (ie, there should be three chemical dissociation stages connected by two equilibrium arrows, given below): b) Below is an idealized titration curve showing the exhibited pH for 25.00 mL of a 0.100 M aqueous carbonic acid solution as a function of added 0.100 M NaOH in units...
3. Consider the following weak acids and their K, values, calculate the pK, for each acid. HC,H,O, - Acetic acid K. = 1.8 x 105 PK,= H,PO, - Phosphoric acid K = 7.1 x 10 PK, HCIO - Hypochlorous acid K = 3.5 x 10 pk = You want to prepare buffers at pH 2.8, 4.5 and 7.5. Which weak acid-conjugate base buffer system is the best choice for each pH from the acids listed? Write the reaction and indicate...
1. Write the dissociation reaction and the corresponding K, equilibrium expression for each of the following )HCN bHOC.H 2. You may need Table 14.2 to answer the following questions a) Which is the stronger base, CT or HO b) Which is the stronger base, HiO or NO? c) which is the stronger base, Cr or OCH,7 3. Calculate the [H"1 of each of the following solutions at 25 C. Identity each solution as neutral, acidic, or basic. a) [OH] ....
in some cases, there may be a mixture of two or more acids. When this happens, the stronger acid will dissociate completely, so you should be able to calculate how much H,0 is in solution as a result. Writing out the equation for the dissociation often helps The weak acid will attempt to dissociate and is governed by the equilibrium (K,). You should write out the equation for the weak acid Now-write in the values for the concentrations that you'll...
Consider the following control system: R + Let G(s) s +23-3 and H(s) K where K is some positive constant. The transfer function H(s) can be considered a proportional feedback controller. (a) Examine the behavior of the system for different values of K. Try the values K 2, 4, 8. In each case, plot the pole-zero map of the closed-loop system and examine the step response. Comment on the stability of the system. Find the value of K for which...