Chemical Equilibrium: Finding a Constant, Kc

  1. Click  to begin data collection.
  2. Empty the water from the cuvette. Rinse it twice with ~1 mL portions of the Test Tube 1 solution.
  3. Wipe the outside of the cuvette with a tissue and then place the cuvette in the Colorimeter. After closing the lid, wait for the absorbance value displayed in the meter to stabilize. Then click , type “1” (the trial number) in edit box, and press the ENTER key.
  4. Discard the cuvette contents as directed by your teacher. Rinse the cuvette twice with the Test Tube 2 solution and fill the cuvette 3/4 full. Follow the Step-c procedure to find the absorbance of this solution. Type “2” in the edit box and press ENTER.
  5. Repeat the Step d procedure to find the absorbance of the solutions in Test Tubes 3, 4, and 5 (the standard solution).
  6. From the table, record the absorbance values for each of the five trials in your data table.
  7. Dispose of all solutions as directed by your instructor.


1.   Write the Kc expression for the reaction in the Data and Calculation table.

   2.   Calculate the initial concentration of Fe3+, based on the dilution that results from adding KSCN solution and water to the original 0.0020 M Fe(NO3)3 solution. See Step 2 of the procedure for the volume of each substance used in Trials 1-4. Calculate [Fe3+]i using the equation:

[Fe3+]i =  Í (0.0020 M)

      This should be the same for all four test tubes.

   3.   Calculate the initial concentration of SCN, based on its dilution by Fe(NO3)3 and water:

 [SCN]i = Í (0.0020 M)

      In Test Tube 1, [SCN]i = (2 mL / 10 mL)(0.0020 M) = 0.00040 M. Calculate this for the other three test tubes.

   4.   [FeSCN2+]eq is calculated using the formula:

 [FeSCN2+]eq =  Í [FeSCN2+]std

      where Aeq and Astd are the absorbance values for the equilibrium and standard test tubes, respectively, and [FeSCN2+]std = (1/10)(0.0020) = 0.00020 M. Calculate [FeSCN2+]eq for each of the four trials.

   5.   [Fe3+]eq: Calculate the concentration of Fe3+ at equilibrium for Trials 1-4 using the equation:

 [Fe3+]eq = [Fe3+]i – [FeSCN2+]eq

   6.   [SCN]eq: Calculate the concentration of SCN- at equilibrium for Trials 1-4 using the equation:

 [SCN]eq = [SCN]i – [FeSCN2+]eq

7.   Calculate Kc for Trials 1-4. Be sure to show the Kc expression and the values substituted in for each of these calculations.

8.   Using your four calculated Kc values, determine an average value for Kc. How constant were your Kc values?

Research Paper 101
Calculate your paper price
Pages (550 words)
Approximate price: -

Reasons to trust Research Paper 101

On Time Delivery

We pride ourselves in meeting the deadlines of our customers. We take your order, assign a writer but allow some more time for ourselves to edit the paper before delivering to you. You are guaranteed a flawless paper on a timely manner...

24x7 Customer Live Support

Our team at Research Paper 101 is committed to handling your paper according to the specfications and are available 24*7 for communication. Whenever you need a quick help, you can talk to our writers via the system messaging or contact support via live chat and we will deliver your message instantly.

Experienced Subject Experts

Online Experts from Research Paper 101 are qualified both academically and in their experiences. Many are Masters and Phd holders and therefore, are qualified to handle complex assignments that require critical thinking and analyses...

Customer Satisfaction

We offer dissertation papers as per students’ wishes. We also help craft out the best topics and design concept papers. By ordering with us, you are guaranteed of defending and making through those hard faced professors in the defense panel!

100% Plagiarism Free

We at Research Paper 101 take plagiarism as a serious offence. From the start, we train our writers to write all their papers from scratch. We also check if the papers have been cited appropriately. Our website also has a tool designed to check for plagiarism that has been made erroniusly. In essense, the paper you get will be 100% legit...

Affordable Prices

We understand that being a student is very challenging, some students balance between work and studies in order to survive. We therefore offer pocket friendly rates that are very competitive in the market.

Try it now!

Calculate the price of your order

Total price:

How it works?

Follow these simple steps to get your paper done

Place your order

Fill in the order form and provide all details of your assignment.

Proceed with the payment

Choose the payment system that suits you most.

Receive the final file

Once your paper is ready, we will email it to you.

Our Services

No need to work on your paper at night. Sleep tight, we will cover your back. We offer all kinds of writing services.


Essay Writing Service

No matter what kind of academic paper you need and how urgent you need it, you are welcome to choose your academic level and the type of your paper at an affordable price. We take care of all your paper needs and give a 24/7 customer care support system.


Admission Essays & Business Writing Help

An admission essay is an essay or other written statement by a candidate, often a potential student enrolling in a college, university, or graduate school. You can be rest assurred that through our service we will write the best admission essay for you.


Editing Support

Our academic writers and editors make the necessary changes to your paper so that it is polished. We also format your document by correctly quoting the sources and creating reference lists in the formats APA, Harvard, MLA, Chicago / Turabian.


Revision Support

If you think your paper could be improved, you can request a review. In this case, your paper will be checked by the writer or assigned to an editor. You can use this option as many times as you see fit. This is free because we want you to be completely satisfied with the service offered.