2. What is the path length (b) ? What is the molar extinction coefficient (E) ?

Fundamentals Of Analytical Chemistry
9th Edition
ISBN:9781285640686
Author:Skoog
Publisher:Skoog
Chapter31: Introduction To Analytical Separations
Section: Chapter Questions
Problem 31.26QAP
icon
Related questions
Question

I keep asking for help and Im getting rejected someone please help me I'm very confused

Lab 1: Equilibrium Constant Determination

 

You will have to determine the equilibrium constant for the reaction between aqueous iron(III) ion and thiocyanate ion. The equilibrium equation is given below:

Fe3+ (aq) + NCS (aq) <---> FeNCS2+ (aq)

yellow          colorless             red

The absorbance of light is measured using a spectrophotometer. The higher the absorbance, the higher the concentration of FeNCS2+ present.

At room temperature, 5.00ml of 0.200M iron(III)nitrate solution was mixed with 5.00ml of 0.200M potassium thiocyante solution. The absorbance of this mixture was 0.55. A 1cm thick cuvette was used.

1- What is the Beer-Lambert Law?

The Beer-Lambert Law relates the attenuation of light to the properties of the material through which the light is travelling. In other words “The path length and concentration of a chemical are directly proportional to its absorption of light.” A = ԐCl

2. What is the path length (b) ? What is the molar extinction coefficient (E) ?

Slope= 5420.3

A =A0 + ԐCl

The slope is Ԑl.

Both the slopes will equal.

Ԑl = 5420.3

the cuvette is 1 cm in diameter that means the path length is also 1 cm. So,

Ԑl= 5420.3/1=5420.3 M−1cm−1

3. What is the equilibrium concentration of iron(III)thiocyante of our solution?

 

4. What are the equilibrium concentrations of Fe3+ and SCN- in our solution?

 

5. What is the equilibrium constant for the reaction at room temperature?

 

6. If we had used a temperature different the room temp, would that change our equilibrium constant? Explain your answer.

Analysis of Fe-SCNequilibrium
y = 5420.3x - 0.0059
0.25
0.2
0.15
0.1
0.05
-0.05
0.0000
0.00002
0.000030.00004
0.00005
[Fe-SCN product] (M)
Abs @ 487 nm
Transcribed Image Text:Analysis of Fe-SCNequilibrium y = 5420.3x - 0.0059 0.25 0.2 0.15 0.1 0.05 -0.05 0.0000 0.00002 0.000030.00004 0.00005 [Fe-SCN product] (M) Abs @ 487 nm
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 2 steps with 1 images

Blurred answer
Knowledge Booster
Coordination Complexes
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.
Similar questions
  • SEE MORE QUESTIONS
Recommended textbooks for you
Fundamentals Of Analytical Chemistry
Fundamentals Of Analytical Chemistry
Chemistry
ISBN:
9781285640686
Author:
Skoog
Publisher:
Cengage
Principles of Instrumental Analysis
Principles of Instrumental Analysis
Chemistry
ISBN:
9781305577213
Author:
Douglas A. Skoog, F. James Holler, Stanley R. Crouch
Publisher:
Cengage Learning
Appl Of Ms Excel In Analytical Chemistry
Appl Of Ms Excel In Analytical Chemistry
Chemistry
ISBN:
9781285686691
Author:
Crouch
Publisher:
Cengage