Explanation H 2 A is a polyprotic acid. It is strong acid in its first deprotonation. Therefore, to estimate its p H , the second deprotonation needs to be taken in account. The first and second deprotonation reactions are given below. H 2 A ( a q ) + H 2 O ( l ) → H 3 O + ( a q ) + H A − ( a q ) H A − ( a q ) + H 2 O ( l ) ⇌ H 3 O + ( a q ) + A 2 − ( a q ) , K a 2 The expression for equilibrium constant for the above reaction can be written as shown below, K a 2 = [ H 3 O + ] [ A 2 − ] [ H A − ] The conjugate base H A − is amphiprotic and it contributes protons to the solution which has been shown in the second deprotonation reaction above. An equilibrium table can be set up as given below. C o m p o s i t i o n ( M ) H A − H 2 O H 3 O + A 2 − I n i t i a l c o n c e n t r a t i o n 0.015 − 0.015 0 C h a n g e i n c o n c e n t r a t i o n − x − + x + x E q u i l i b r i u m c o n c e n t r a t i o n 0.015 − x − 0.015 + x x Now, these values in the fourth row can be inserted in the equilibrium constant expression as shown below

7th Edition

ISBN: 9781319421175

Author: ATKINS

Publisher: MAC HIGHER

See similar textbooks

Concept explainers

Electrolysis

Electrolysis is defined as the process of breaking down ionic compounds into their constituent elements by passing a direct electric current through the compound in a fluid state. The cathode reduces cations, while the anode oxidizes anions. An electroly…

Videos

Question

Chapter 6, Problem 6E.8E

Interpretation Introduction

Interpretation:

The value of Ka2 for the acid H2A has to be calculated.

Expert Solution & Answer

Want to see the full answer?

Check out a sample textbook solution

See solution

Chapter 6, Problem 6E.7E

Chapter 6, Problem 6E.9E

Students have asked these similar questions

Consider the titration of a 50.00 mL sample of 0.500 M hydrazoic acid, HN3, with 0.500 M NaOH (aq., 25 oC). The Ka HN3 = 4.50 x 10–4. What is the pH of the solution after 15.00 mL of NaOH has been added?

Write the equilibrium constant expression, K, for the following reaction taking place in dilute aqueous solution. HNO2(aq) + H,O(1)=H30*(aq) + NO2 (aq)

Consider the following galvanic cell reaction at 25 oC, 4 Cr2+(aq) + O2(g) + 4 H3O+(aq) → 4 Cr3+(aq) + 6 H2O(l). Which of thefollowing statements best describes what would happen to the cell potential if the concentration of Cr2+ is increased?(a) The cell potential would become less positive.(b) The cell potential would become more positive.(c) The cell potential would remain the same.(d) It is impossible to tell.

Chapter 6 Solutions

CHEMICAL PRINCIPLES (LL) W/ACCESS

Ch. 6 - Prob. 6A.1AST Ch. 6 - Prob. 6A.1BST Ch. 6 - Prob. 6A.2AST Ch. 6 - Prob. 6A.2BST Ch. 6 - Prob. 6A.3AST Ch. 6 - Prob. 6A.3BST Ch. 6 - Prob. 6A.1E Ch. 6 - Prob. 6A.2E Ch. 6 - Prob. 6A.3E Ch. 6 - Prob. 6A.4E

Knowledge Booster

Learn more about

Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, chemistry and related others by exploring similar questions and additional content below.