Loading...

Messages

Proposals

Stuck in your homework and missing deadline? Get urgent help in $10/Page with 24 hours deadline

Get Urgent Writing Help In Your Essays, Assignments, Homeworks, Dissertation, Thesis Or Coursework & Achieve A+ Grades.

Privacy Guaranteed - 100% Plagiarism Free Writing - Free Turnitin Report - Professional And Experienced Writers - 24/7 Online Support

How to find ksp from absorbance

18/03/2021 Client: saad24vbs Deadline: 2 Day

Determining the Equilibrium Constant of a Chemical Reaction

Purpose To determine the equilibrium constant, Kc (also called Kf) for the formation of a complex ion by measuring equilibrium concentrations of the reacting species involved. Introduction Many methods may be used to determine the equilibrium constant for a given system. A pH meter may be used to determine the acid dissociation constant, Ka, and it is also possible to determine the solubility product equilibrium constant, Ksp. However in this experiment the equilibrium constant, Kc, for the formation of a complex ion will be determined by measuring the concentrations of reactants in the reaction below. The equilibrium expression is also shown below.

Fe3+(aq) + SCN- (aq) FeSCN2+ (aq) 𝐾𝑐 = [𝐹𝑒𝑆𝐢𝑁2+]

[𝐹𝑒3+][π‘†πΆπ‘βˆ’]

The FeSCN2+ complex ion is a strongly colored species; therefore the reaction can be investigated using spectroscopy. In part A, a calibration curve will be constructed using FeSCN2+ solutions of known concentration. Each standard solution contains a large excess of Fe3+ to ensure all SCN- in solution forms the FeSCN2+ complex. Therefore, the concentration of FeSCN2+ at equilibrium is equal to the initial concentration of SCN-. The calibration curve will be used to determine the equilibrium concentration of FeSCN2+ of each sample (prepared in part B) containing similar concentrations of Fe3+ and SCN- at equilibrium. In part B, mixtures containing similar concentrations of Fe3+ and SCN- will be prepared. Each solution will be allowed to reach equilibrium such that the following mass balance equations (1) and (2) are valid. With these equations and the initial concentration of the two ions the equilibrium concentrations can be determined.

[Fe3+]initial = [Fe3+]eq + [FeSCN2+]eq (1)

[SCN- ] initial = [SCN- ] eq + [FeSCN2+] eq (2)

An alternate and probably more familiar way to determine equilibrium concentrations is the ICE box method. The ICE box method uses the same equations as above but arranges them in a chart like format.

Fe3+(aq) + SCN- (aq) FeSCN2+ (aq)

Initial I

Change 

Equilibrium Eq

The initial concentrations of iron Fe3+ and thiocyanate SCN- ions can be easily determined from the concentration of the stock solutions. The absorbance of the iron thiocyanate ion will be determined by spectroscopy and compared with the calibration curve prepared in part A to determine the equilibrium concentration of the ion. The equilibrium concentrations can be found using the ICE box chart.

Short Review of Beer’s Law & Spectroscopy Beer’s Law is defined below in equation: A = a b c In the equation, A is the measured absorbance of the sample, b is the path length of light through the sample, c is the concentration of the sample, and a is a constant that depends on both wavelength and substance. A linear calibration curve, or Beer’s Law plot, of absorbance (y-axis) versus concentration (x-axis) can be constructed from the absorbance and concentration data of standard solutions. A prepared calibration curve can be used to determine the concentration of an unknown solution from its measured absorbance. Experimental Procedure: General Instructions – Read this BEFORE proceeding to Parts A and B. 1. The SpectroVis Spectrometers and LabQuest units will be used for this experiment. The

spectrometers need to be calibrated using the blank solutions for Part A and Part B respectively. See the procedure below for instructions on calibrating the spectrometer. The wavelength to be monitored for all samples is 460 nm.

2. There are four solutions used in this experiment. Do not take more solution than you need and do

not cross contaminate the solutions.

ο‚· Obtain two burets to deliver the 0.004 M Fe3+ and 0.004 M SCN- solutions. The burets must be clean prior to use. Be sure to rinse the buret with a few mL of the solution prior using.

ο‚· Use your 10.00 mL pipet for the 0.1 M Fe3+. ο‚· Use a graduated cylinder for the 1.0 M HNO3 and DI water. You can use a plastic pipet to

accurately fill the cylinder.

For each solution record the exact volumes you deliver in your data tables (and notebook) with the correct number of significant digits.

3. Prepare all solutions in test tubes large enough to hold 20 mL (provided). 4. Thoroughly mix all solutions by stoppering the tube and inverting at least five times. If the

solutions are not properly mixed there will be significant error in your results. 5. DO NOT PREPARE solutions for part B until you have completed Part A. Instrument Setup and Calibration 1. In the menu bar select Sensors then choose Data Collection. Select the dropdown arrow next to

the Mode box and choose the Time Based option. Leave other settings as is. Tap OK. 2. In the menu bar select Sensors, then choose Calibrate, and select USB:Spectrometer. A

calibration page should appear. Tap OK. 3. After the warm-up period obtain a cuvette filled with water to calibrate the spectrometer. Tap

the Finish Calibration button. When the unit states calibration complete tap OK. 4. Back on the main screen, tap the panel labeled USB: Abs. Select Change Wavelength from the

menu. 5. For the Selected Wavelength enter 460 nm. Tap OK when done.

Part A: Construction of Beer’s Law Plot

1. Prepare blank A and samples 1A – 4A using the 0.10 M Fe3+ solution according to the volumes listed below. Since the measured volumes may vary slightly from the volumes in the table below, record the exact volume of each reagent used in Table 1 on page 5.

Sample Volume (mL) of

0.10 M Fe3+ Volume (mL) of

0.004 M SCN- Volume (mL) of

1.0 M HNO3 Volume (mL) of Deionized H2O

Blank A 10.00 0.00 5.0 5.0

1A 10.00 0.30 5.0 4.7

2A 10.00 0.60 5.0 4.4

3A 10.00 1.20 5.0 3.8

4A 10.00 2.00 5.0 3.0

2. Calibrate the spectrometer with water. When calibrated obtain an absorbance reading for the

Blank A solution. This will be used to correct for any background absorbance in the samples. 3. Record the absorbance of each sample in Table 2 (in your notebook). 4. Calculate the concentration of [FeSCN2+]eq and place the value in Table 2 (in your notebook). NOTE: a) [FeSCN2+]eq = [SCN- ]initial. This is true only for part A

Homework is Completed By:

Writer Writer Name Amount Client Comments & Rating
Instant Homework Helper

ONLINE

Instant Homework Helper

$36

She helped me in last minute in a very reasonable price. She is a lifesaver, I got A+ grade in my homework, I will surely hire her again for my next assignments, Thumbs Up!

Order & Get This Solution Within 3 Hours in $25/Page

Custom Original Solution And Get A+ Grades

  • 100% Plagiarism Free
  • Proper APA/MLA/Harvard Referencing
  • Delivery in 3 Hours After Placing Order
  • Free Turnitin Report
  • Unlimited Revisions
  • Privacy Guaranteed

Order & Get This Solution Within 6 Hours in $20/Page

Custom Original Solution And Get A+ Grades

  • 100% Plagiarism Free
  • Proper APA/MLA/Harvard Referencing
  • Delivery in 6 Hours After Placing Order
  • Free Turnitin Report
  • Unlimited Revisions
  • Privacy Guaranteed

Order & Get This Solution Within 12 Hours in $15/Page

Custom Original Solution And Get A+ Grades

  • 100% Plagiarism Free
  • Proper APA/MLA/Harvard Referencing
  • Delivery in 12 Hours After Placing Order
  • Free Turnitin Report
  • Unlimited Revisions
  • Privacy Guaranteed

6 writers have sent their proposals to do this homework:

Engineering Mentor
Top Academic Guru
Homework Guru
Math Exam Success
Innovative Writer
Calculation Guru
Writer Writer Name Offer Chat
Engineering Mentor

ONLINE

Engineering Mentor

I am known as Unrivaled Quality, Written to Standard, providing Plagiarism-free woork, and Always on Time

$100 Chat With Writer
Top Academic Guru

ONLINE

Top Academic Guru

I have read and understood all your initial requirements, and I am very professional in this task.

$81 Chat With Writer
Homework Guru

ONLINE

Homework Guru

Hello, I an ranked top 10 freelancers in academic and contents writing. I can write and updated your personal statement with great quality and free of plagiarism

$54 Chat With Writer
Math Exam Success

ONLINE

Math Exam Success

You can award me any time as I am ready to start your project curiously. Waiting for your positive response. Thank you!

$90 Chat With Writer
Innovative Writer

ONLINE

Innovative Writer

Hello, I an ranked top 10 freelancers in academic and contents writing. I can write and updated your personal statement with great quality and free of plagiarism

$61 Chat With Writer
Calculation Guru

ONLINE

Calculation Guru

Give me a chance, i will do this with my best efforts

$99 Chat With Writer

Let our expert academic writers to help you in achieving a+ grades in your homework, assignment, quiz or exam.

Similar Homework Questions

Arguments against keeping animals in zoos - Autoenginuity download free full - Dielectric constant of plywood - The walt disney company the entertainment king case analysis - Communicating using video conferencing and E-GROUP - Evidence-based practice (EBP - Melodic musical sales inc. is located at 5500 - Essential business concepts - Masters Assistance - Application of double integral - JCCMI- Week 6 Discussion 1 and 2 - Alpha phi omega hazing - Brazil's dance with the devil summary - A & P II #4 - If zappos wanted to utilize data mining they might - Discussion: Electronic Health Records Impact on Health Care - Yellowstone wolves food web - MGT - Value Creation in Organizations - Abnormal situation management ppt - Watson's 10 carative factors - Solve the equation calculator - The ways we lie multiple choice answer key - Y 3 2x 2 parabola - Nektan Casino - Introduction accounting assignment - Gravimetric analysis of a soluble chloride lab report - How to find the linear correlation coefficient on statcrunch - 7 kinloch court nerrina - Bridgestone tg australia pty ltd - They say i say is college the best option - Ethics - Cultural relativism and universal human rights by carolyn fluehr lobban - Toll group my parcel - Linear expansion apparatus parts and function - Le reve perfume chemist warehouse - Proj 587 week 5 case study - Ops 571 process improvement presentation - La profesora cruz prepara la prueba - Myunisa student home page - Pizza ordering system project - Historical-Cultural Background - Gem explorer course matching - Dr arucha ekeowa anderson - Ka ba and akh - Planning marketing partnering to build customer relationships - 12 angry men audiobook - Which element would most likely have a positive electron affinity - Causes of being underweight - Bob dylan the times they are a changin lyrics - The norton introduction to literature portable 13th edition pdf - Walt disney corporate strategy and business development - Buying and selling business math formulas - Healthiertogether medtronic com - Write an algorithm to brush your teeth - Shrek the musical characters - Assignment #41 - Case Study - Pros and cons of lifelong learning - Cocoon dvr invalid password - Crime Analysis Report - Building the great wall of china documentary - Bibliography of drought in cape town - A forecast with a large cumulative sum of forecast errors (cfe) indicates - Responding to ethical dilemmas - Access Control discussion 3 - Lab Report - Ask bethany updated edition bethany hamilton - Lesson plan and rationale - Business Scandal - Managment - Donatos finding the new pizza - Acceleration practice problems answer key - Popping an element from an empty stack is called ____. - Shape of a hand - Define marketing myopia give three examples in the sport industry - Hector gaming company case study pdf - Literacy pre assessment quiz gcu - How is professional writing different from other writing - Antoine equation excel solver - Compression ignition engine management systems - The musical experience 3rd edition assignment answers - I need a 470 words on copywrite project on 32 short messages template in English need to reform. - Writing for the mass media 9th edition answers - Articulations a unlv rhetoric and reader 2nd edition pdf - Ritz carlton dubai wikipedia - Pinewood holiday park narberth - Cycad blue butterfly larvae - Team Project -- my part - Forward premium or discount formula - Professor sri prasad urology - Flinders street station ballroom renovation - Bmw isetta club australia - Scientific variables worksheet answers - LecciΓ³n 4 contextos describir audio - Www drugabuse gov publications drugfacts high school youth trends - Simulation - Walter cunningham sr quotes - Paper - Global business concepts methodologies tools and applications