(a) Interpretation: Absorbance values of the conjugate acid-base pair solutions of different concentrations at 430 nm and 600 nm should be calculated. Concept introduction: The absorbance can be calculated using the following formula: A = ε bc Where, A = absorbance ε = molar absorptivity b = path length in cm c = concentration of the sample The total absorbance of a conjugate acid-base solution can be calculated as below, HIn ⇔ H + + In − A = ε In - b[In - ] + ε HIn b[HIn - ] For the given conjugate acid-base pair, equilibrium can be written as, HIn + H 2 O ⇔ H 3 O + + In − K a = 8.00 × 10 − 5 = [ H + ] [ In − ] [ HIn ]

BuyFind

Principles of Instrumental Analysis

7th Edition
Douglas A. Skoog + 2 others
Publisher: Cengage Learning
ISBN: 9781305577213
BuyFind

Principles of Instrumental Analysis

7th Edition
Douglas A. Skoog + 2 others
Publisher: Cengage Learning
ISBN: 9781305577213

Solutions

Chapter 13, Problem 13.11QAP
Interpretation Introduction

(a)

Interpretation:

Absorbance values of the conjugate acid-base pair solutions of different concentrations at 430 nm and 600 nm should be calculated.

Concept introduction:

The absorbance can be calculated using the following formula:

A = εbcWhere, A = absorbanceε = molar absorptivityb = path length in cmc = concentration of the sampleThe total absorbance of a conjugate acid-base solution can be calculated as below,HIn  H+ + InA = εIn-b[In-] + εHInb[HIn-]

For the given conjugate acid-base pair, equilibrium can be written as,

HIn + H2O H3O+ + InKa=8.00×105=[H+][In][HIn]

Interpretation Introduction

(b)

Interpretation:

Absorbance as a function of indicator concentration should be plotted.

Want to see the full answer?

Check out a sample textbook solution.

Want to see this answer and more?

Experts are waiting 24/7 to provide step-by-step solutions in as fast as 30 minutes!*

*Response times may vary by subject and question complexity. Median response time is 34 minutes for paid subscribers and may be longer for promotional offers.