The document describes an experiment to determine the equilibrium constant (Kc) for the reaction of iron (III) and thiocyanate ions to form iron (III) thiocyanate. It involves:
1. Creating a calibration curve by measuring the absorbance of solutions with known iron (III) thiocyanate concentrations. This establishes the relationship between concentration and absorbance.
2. Measuring the absorbance of solutions with unknown iron (III) thiocyanate concentrations. The calibration curve is used to determine these concentrations.
3. Setting up ICE tables to calculate Kc using the equilibrium concentrations determined from absorbance measurements and concentrations of initial reactants.
Simultaneous determination of chromium and cobalt in a solution by visible sp...Haydar Mohammad Salim
If two or more absorbing species are present in the solution, the Beer-Lambert law predicts that for a given wavelength, values of individual absorbances sum up, as shown below:
A = A1+A2+A3+.....+An = (ε1·c1+ε2·c2+ε3·c3+.....+ε n·cn)·
I hope it might be helpful to you.
Email me on sidhu.s.karanvir@gmail.com to see more work.
Follow me at Linkedln
https://www.linkedin.com/in/karanvir-sidhu-b6995864/
Simultaneous determination of chromium and cobalt in a solution by visible sp...Haydar Mohammad Salim
If two or more absorbing species are present in the solution, the Beer-Lambert law predicts that for a given wavelength, values of individual absorbances sum up, as shown below:
A = A1+A2+A3+.....+An = (ε1·c1+ε2·c2+ε3·c3+.....+ε n·cn)·
I hope it might be helpful to you.
Email me on sidhu.s.karanvir@gmail.com to see more work.
Follow me at Linkedln
https://www.linkedin.com/in/karanvir-sidhu-b6995864/
Chemistry Lab Report on standardization of acid and bases. Karanvir Sidhu
I hope it might be helpful to you.
Email me on sidhu.s.karanvir@gmail.com to see more work.
Follow me at Linkedln
https://www.linkedin.com/in/karanvir-sidhu-b6995864/
Chemistry Lab Report on standardization of acid and bases. Karanvir Sidhu
I hope it might be helpful to you.
Email me on sidhu.s.karanvir@gmail.com to see more work.
Follow me at Linkedln
https://www.linkedin.com/in/karanvir-sidhu-b6995864/
In this laboratory exercise we will separate and identify Cations dissolved in an Aqueous system. Since we will not quantify the amount of each Cation present, but instead merely discern its presence, such a scheme for separation and identification is referred to as a Qualitative Analysis. In our particular case, we will be testing for the presence of the following nine Cations:
Ag+, Pb2+, Cu2+, Bi3+, Fe3+, Mn2+, Ni2+, Ba2+, Na+
Infrared spectroscopy (IR spectroscopy) is the spectroscopy that deals with the infrared region of the electromagnetic spectrum, that is light with a longer wavelength and lower frequency than visible light. It covers a range of techniques, mostly based on absorption spectroscopy. As with all spectroscopic techniques, it can be used to identify and study chemicals. A common laboratory instrument that uses this technique is a Fourier transform infrared (FTIR) spectrometer.
Laboratory Manual for Semester 4: Physical and Analytical Chemistry ExperimentsAQEELAABDULQURESHI
The pdf provides theory, procedure and calculations of physical and analytical chemistry experiments (Conductometry, Potentiometry and Chemical Kinetics) of semester IV as per revised syllabus of Mumbai University, effective from academic year 2017-18.
PHOTOCHEMISTRY BASIC PRINCIPLE AND JABLONSKI DIAGRAMsuriyachem27
Photochemistry is the branch of chemistry in which study of chemical reactions take place by
the absorption of electromagnetic radiation or by molecules absorb light radiation
(electromagnetic radiation) particularly the visible (wavelength from (400-750) and ultra violet region (wavelength from 100-400nm ), the molecules generally get activated due to
electronic excitation. When electromagnetic radiation is absorb in the ultraviolet/visible
region the molecules get excited to higher electronic state. This involves the promotion of an
electron from bonding molecular orbital to antibonding molecular orbital. According to the quantum theory, both matter and light are quantised, and only certain
specific energies of light are absorbed by specific organic molecule for its excitation. The
absorption or emission of light occurs by the transfer of energy as photons. All photochemical and photo physical processes are initiated by the absorption of a photon of visible or ultraviolet radiation leading to the formation of an electronically - excited state. The molar absorptivity (formerly called the extinction coefficient) of a compound constant
that is characteristic of the compound at a particular wavelength. The Jablonski diagram is a pictorial illustrated of different energy states which are absorbed by molecules. This
partial energy diagram represents the energy of a photo luminescent molecule in its different energy states.The life time of singlet excited state S1 is long hence in this state has done many physical and chemical processes. Molecules returns to its ground state, S0 from excited singlet S1,/ S2 state by release energy as heat, but this is generally quite slow because the amount of energy is large between S0 and S1. This process is called internal conversion. When molecules return to its ground state S0 from excited state S1,/ S2 by giving off
energy in the light form within 10-9 seconds. This process is known as Fluorescence.
This pathway is not very common because it is relatively slow. For smaller, diatomic
and rigid molecules (mainly aromatic compounds) show fluorescence. This is because
emitted fluorescent light is of lower energy than absorbance light. Most molecules in the S1 state may drop to triplet state (T1) (S1→T1). This is
energetically slow process. However, if the singlet state S1 is long lived, the S1 →
T1 conversion occurs by a process called intersystem crossing. It is important
phenomenon in photochemistry. For every excited singlet state there exist
corresponding triplet states. Since transition from ground state singlet (S0) to triplet
state (T1) is forbidden, intersystem crossing is the main source of excited triplet
state. This is one way of populating the triplet state. The efficiency in intersystem
crossing depends on the S1 → T1 energy gap.
UiPath Test Automation using UiPath Test Suite series, part 4DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 4. In this session, we will cover Test Manager overview along with SAP heatmap.
The UiPath Test Manager overview with SAP heatmap webinar offers a concise yet comprehensive exploration of the role of a Test Manager within SAP environments, coupled with the utilization of heatmaps for effective testing strategies.
Participants will gain insights into the responsibilities, challenges, and best practices associated with test management in SAP projects. Additionally, the webinar delves into the significance of heatmaps as a visual aid for identifying testing priorities, areas of risk, and resource allocation within SAP landscapes. Through this session, attendees can expect to enhance their understanding of test management principles while learning practical approaches to optimize testing processes in SAP environments using heatmap visualization techniques
What will you get from this session?
1. Insights into SAP testing best practices
2. Heatmap utilization for testing
3. Optimization of testing processes
4. Demo
Topics covered:
Execution from the test manager
Orchestrator execution result
Defect reporting
SAP heatmap example with demo
Speaker:
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
Smart TV Buyer Insights Survey 2024 by 91mobiles.pdf91mobiles
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JMeter webinar - integration with InfluxDB and GrafanaRTTS
Watch this recorded webinar about real-time monitoring of application performance. See how to integrate Apache JMeter, the open-source leader in performance testing, with InfluxDB, the open-source time-series database, and Grafana, the open-source analytics and visualization application.
In this webinar, we will review the benefits of leveraging InfluxDB and Grafana when executing load tests and demonstrate how these tools are used to visualize performance metrics.
Length: 30 minutes
Session Overview
-------------------------------------------
During this webinar, we will cover the following topics while demonstrating the integrations of JMeter, InfluxDB and Grafana:
- What out-of-the-box solutions are available for real-time monitoring JMeter tests?
- What are the benefits of integrating InfluxDB and Grafana into the load testing stack?
- Which features are provided by Grafana?
- Demonstration of InfluxDB and Grafana using a practice web application
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https://www.rttsweb.com/jmeter-integration-webinar
Securing your Kubernetes cluster_ a step-by-step guide to success !KatiaHIMEUR1
Today, after several years of existence, an extremely active community and an ultra-dynamic ecosystem, Kubernetes has established itself as the de facto standard in container orchestration. Thanks to a wide range of managed services, it has never been so easy to set up a ready-to-use Kubernetes cluster.
However, this ease of use means that the subject of security in Kubernetes is often left for later, or even neglected. This exposes companies to significant risks.
In this talk, I'll show you step-by-step how to secure your Kubernetes cluster for greater peace of mind and reliability.
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Create a campaign using Mailchimp with merge tags/fields
Send an interactive Slack channel message (using buttons)
Have the message received by managers and peers along with a test email for review
But there’s more:
In a second workflow supporting the same use case, you’ll see:
Your campaign sent to target colleagues for approval
If the “Approve” button is clicked, a Jira/Zendesk ticket is created for the marketing design team
But—if the “Reject” button is pushed, colleagues will be alerted via Slack message
Join us to learn more about this new, human-in-the-loop capability, brought to you by Integration Service connectors.
And...
Speakers:
Akshay Agnihotri, Product Manager
Charlie Greenberg, Host
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We believe integration and automation are essential to user experience and the promise of efficient work through technology. Automation is the critical ingredient to realizing that full vision. We develop integration products and services for Bonterra Case Management software to support the deployment of automations for a variety of use cases.
This video focuses on the notifications, alerts, and approval requests using Slack for Bonterra Impact Management. The solutions covered in this webinar can also be deployed for Microsoft Teams.
Interested in deploying notification automations for Bonterra Impact Management? Contact us at sales@sidekicksolutionsllc.com to discuss next steps.
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The publishing industry has been selling digital audiobooks and ebooks for over a decade and has found its groove. What’s changed? What has stayed the same? Where do we go from here? Join a group of leading sales peers from across the industry for a conversation about the lessons learned since the popularization of digital books, best practices, digital book supply chain management, and more.
Link to video recording: https://bnctechforum.ca/sessions/selling-digital-books-in-2024-insights-from-industry-leaders/
Presented by BookNet Canada on May 28, 2024, with support from the Department of Canadian Heritage.
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GDG Cloud Southlake #33: Boule & Rebala: Effective AppSec in SDLC using Deplo...James Anderson
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Bob Boule
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Gopinath Rebala
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401 expt2 revamp this
1. 3
Experiment 2: Determination of the Equilibrium Constant For Iron Thiocyanate
The data for this lab will be taken as a class to get one data set for the entire class.
I. Introduction
The Spectrophotometer
Substances are colored when they absorb a particular wavelength of light in the visible region and transmit
the other wavelengths. Complex ions such as FeSCN2+
usually absorb light in the visible range; the color
we see is the sum of the transmitted wavelengths.
A spectrophotometer is an instrument that separates visible light into its component wavelengths and then
measures the amount of light absorbed by the solution at a particular wavelength. The essential parts of a
spectrophotometer are shown below:
Figure 1: Schematic of the important parts of the spectrophotometer1
where the instrument has four main parts:
1. A light source that produces light with a range of visible wavelengths,
2. A diffraction grating and aperture that select one wavelength (λ = 447 nm) to pass through the
sample,
3. The sample that is stored in a cuvette with a precisely known and reproducible path length,
usually 1.00 cm and
4. A detector that measures the amount of light hitting its surface.
So what is it that the Spectronic 20 is measuring? It is measuring the amount of light that is transmitted
through your sample and hits the detector as a percentage of the light transmitted with a “blank” sample,
% T =
I
Io
×100%
2. 4
where %T is the percent transmittance, I is the amount of light that is transmitted through the sample and Io
is the amount of light transmitted through the blank, a sample that doesn’t absorb at all. What we would
like to know is slightly different: how much light is being absorbed by our sample? The absorbance is
defined as,
A = –log
I
Io
The absorbance, A, of an ideal solution is directly proportional to the concentration of absorbing ions or
molecules in that solution. The equation that relates absorbance to concentration is known as Beer’s Law,
A = ε l c (2)
where ε is called the extinction coefficient, an attribute that is specific to the absorbing species (at λ = 447
nm, ε is a constant), l is the width of the cuvette (another constant) which contains the solution that is being
analyzed and c is the concentration of the absorbing species expressed as molarity, M. The absorbing
species in this experiment is FeSCN2+
. Hence, the concentration, c, of FeSCN2+
is directly proportional to
the absorbance of that solution with a y-intercept equal to zero,
A = (constant) c (2)
The constant is the slope of the calibration curve made from the data in Procedure 1. Once the constant is
determined, you can measure the absorbance of any solution and then know its concentration of FeSCN2+
.
Let me restate this with direct reference to the procedure for this lab: once the calibration curve has been
constructed using Procedure 1, then any absorbance you measure in Procedure 3 can be used to calculate
the concentration of FeSCN2+
. It is the concentration of FeSCN2+
that is needed to then determine Kc for
reaction (1).
In this experiment, each group will use different cuvettes. It is imperative that the path length l is constant
for all of these cuvettes. Therefore, each of these cuvettes is made with a width that is precisely 1.00 cm.
Each cuvette is marked with a white line near the lip. This white line must be aligned precisely with the
black groove in the sample holder to ensure that the path length is 1.00 cm.
Determining The Equilibrium Constant
The main purpose of this lab is to determine the equilibrium constant for the complex ion formed by the
reaction of Fe3+
with SCN–
,
Fe3+
(aq) + SCN–
(aq) ↔ FeSCN2+
(aq) (1)
In this experiment, we will be calculating Kc for reaction (1) five different times. Each of those five times,
we will get a different number for Kc. While Kc for this reaction is constant, our attempts to experimentally
measure and calculate Kc will not be constant. There is experimental error, both procedural and human-
made, in this experiment. Therefore, we will take the average of the five experimentally determined values
of Kc.
As noted in lecture and the text, when Kc is >> 1, a reaction is product-favored, goes essentially to
completion and the concentrations of products at equilibrium are much larger than the concentration of
reactants (essentially, there are no reactants left). When Kc is <<1, a reaction is reactant-favored, does not
go at all and the concentrations of reactants at equilibrium are much larger than the concentration of
products (essentially, no products form).
As a hint to the answer for this lab, the value of Kc for reaction (1) is somewhere close to 1 (0.0001 < Kc <
10,000), meaning that the reaction gets stuck somewhere in the middle. What we will see is that we can
3. 5
manipulate the concentrations of reactants to make this reaction either go approximately 50% of the way to
completion or as far as 99.5% to completion. This is the basis for this experiment.
In Procedure 1, the above reaction will go essentially to completion. We will use LeChatelier’s Principle
(the subject of experiment 3-we’re just using it here) to drive the reaction to the right. We will add a known
concentration of Fe3+
. We will then add more than 100 times higher concentration of SCN–
than Fe3+
to the
reaction mixture. Using LeChatelier’s Principle, the excess SCN–
will push the position of equilibrium far
to the right and essentially to completion. The Fe3+
is the limiting reactant and all of the Fe3+
will be reacted
to produce FeSCN2+
. Therefore, the concentration of Fe3+
initially, after accounting for dilution, will be the
equilibrium or final concentration of FeSCN2+
.
As mentioned above when discussing the Spec 20, FeSCN2+
absorbs light at λ = 447 nm. We will construct
a “calibration” or “standard” curve that plots the known [FeSCN2+
] on the x-axis and the absorbance A of
FeCN2+
on the y-axis to establish a linear relationship between these two variables. The power of the
calibration curve is that for any solution containing FeSCN2+ as the only absorbing species, we can
measure the absorbance and use the linear relationship to calculate the [FeSCN2+
]. This is exactly why we
are preparing the calibration curve.
For Procedure 3, we add approximately equal concentrations of Fe3+
and SCN–
. Under these conditions, the
reaction will not go to completion. In fact, we will not know how far the reaction went to completion
because we don’t know the equilibrium constant Kc. However, if we measure the absorbance of the
unknown solutions in Procedure 3, then we can use the calibration curve prepared from Procedure 1 to
calculate what the equilibrium [FeSCN2+
] is in that solution. Once we have the equilibrium [FeSCN2+
], we
can fill in the rest of an ICE table to determine Kc.
To summarize, in this experiment we will:
1. Create a calibration curve by measuring the absorbance of a series of solutions of known
[FeSCN2+
]. For these solutions, reaction (1) will be essentially complete. The calibration should
yield a straight line relationship between [FeSCN2+
] and absorbance.
2. Measure the absorbance of a series of solutions for which [FeSCN2+
] is unknown. For these
solutions, reaction (1) will not be complete, but there is still the same relationship between
absorbance and concentration. Use this relationship and the absorbance to calculate [FeSCN2+
].
3. Determine the value of the equilibrium constant Kc for reaction (1).
II. Experimental
A. Equipment Needed:
From stock room: spectrophotometer cuvettes
Equipment in lab: Spectronic 20-D spectrophotometer, burets, aluminum foil
Chemicals in lab: 5.00×10–3
M KSCN in 0.500 M HCl, 2.00×10–3
M FeNO3 (or FeCl3) in 0.500
M HCl, 0.200 M KSCN in 0.500 M HCl and 0.500 M HCl
B. Disposal:
All chemicals used in this experiment should be disposed of in the proper waste container.
C. Experimental considerations
1. The product formed in this experiment is light sensitive. Direct sunlight will slowly decompose
the product, but room light will not. Use the aluminum foil to wrap around any flasks with
FeSCN2+
solution if you will be waiting for more than an hour to use the spectrophotometer
(which will most likely NOT happen).
4. 6
2. All of the ions in this experiment are dissolved in 0.500 M HCl to prevent the side reactions that
produce other complex ions. Henceforth, we will not mention this fact.
3. Please do not take any more of the standardized solutions than necessary.
D. Procedure 1. Preparing Standard Solutions for Absorbance Measurements.
The data for this procedure will be taken together as a class. For each volume of Fe(NO3)3, at
least three absorbance measurements will be taken. More may be taken if the first three
absorbance measurements are not approximately the same.
1. Turn on the spectrophotometer. It must warm up for 10–15 minutes.
2. Use the micropipette to deliver your assigned volume of 2.00×10–3
M Fe3+
into the 10 or 25 mL
graduated cylinder.
3. Add 2.0 mL of 0.200 M SCN–
to the graduated cylinder. Then dilute with 0.500 M HCl exactly
to the 10.00 mL mark. Use a dropper to deliver the last few drops of HCl
4. Use a glass stir rod to mix the solution until a uniform color is obtained. This may take 1-2
minutes of stirring
5. Pour ≈ 1 mL of solution into a cuvette. Rinse the walls of the cuvette with the solution by tilting
and rotating much like it was a 25 mL buret. Dispose of the 1 mL in a waste beaker. This is
necessary if the cuvette is not dry so that the solution you are putting into the cuvette is not diluted
by water left over in the cuvette from previous washings/measurements.
6. If the spectrophotometer has been warming up for 10-15 minutes, then begin testing the
solutions using procedure 2.
7. Repeat steps 2–5 for as many volumes as requested by the instructor until the instructor is
satisfied with the class’ data set.
E. Procedure 2: Measuring The Absorbance of the Standard Solutions.
1. To standardize the Spectronic 20 meter: 2-step standardizing procedure.
A. Set the wavelength dial to 447 nm. With the cell holder empty, adjust the left knob to
zero transmittance.
B. Fill a cuvette with 0.500 M HCl. Make sure you fill the cuvette more than halfway.
Wipe any fingerprints from the cuvette with a Kim-Wipe (and not a paper towel–the
paper towels scratch the cuvettes), and then place it in the cell holder. Ensure that the
vertical white mark on the cuvette is aligned with the mark in the spectrophotometer.
Close the cover for the sample holder. Adjust the lower right knob until the meter reads
100% transmittance. To scroll between %Transmittance and absorbance, press the
“Mode” button.
2. Rinse the cuvette with the solution to be measured, then fill the cuvette more than halfway.
3. Wipe off fingerprints from the cuvette with a Kim-Wipe. Place the cuvette into the sample
holder, replace the cap, and read and record in Table 1 (which should be taped in your notebook)
the ABSORBANCE, A, (% transmittance may also be recorded but, for our purposes, A has a
direct relationship to the quantity of interest, namely, concentration of iron thiocyanate).
4. Measure the absorbance A for each of the standard solutions.
5. 7
5. Calculate the diluted [Fe3+
] in each of the standard solutions using M1V1 = M2V2. Set this equal
to [FeSCN2+
] in the data table.
6. Once the instructor is satisfied that there will be no more measurements for this part of the lab,
determine the average and standard deviation for each mL of Fe3+
. Any values of absorbance that
are considerably different than the average should be tested using the Q test (see Appendix B:
Statistical Functions). If there are any values thrown out using the Q test, recalculate the average
and standard deviation without these points.
mL Fe3+
soln
(2.00 10–3
M)
diluted [Fe3+
]
=[FeSCN2+
]
Absorbance Values
at 447 nm
Average and
Standard deviation
of Absorbance
7. After approval of your data, discard the solutions into the container in the hood.
F. Procedure 3: Absorbance of Unknown Solutions
1. Prepare solutions with the volumes of 2.00×10–3
M Fe3+
and 5.00×10–3
M SCN–
(not the stuff
used in Procedure 1) indicated in Table A (below) in the graduated cylinder. Fill to 10.00 mL with
0.500 M HCl.
2. As determined by instructor, determine the absorbance of each solution and record the value in
Table 2 until a satisfactory data set is established.
Table A: Volumes for Unknown Solutions
Soln. mL of 2.00 10–3
M Fe3+
mL of 5.00 10–3
M SCN–
A 5 1
B 5 2
C 5 3
D 5 4
E 5 5
6. 8
Soln. mL of Fe3+
(2.00 10–3
M)
mL of SCN–
(5.00 10–3
M)
Absorbance
Values at 447
nm
Average and
Standard deviation
of Absorbance
A
B
C
D
E
III. Calculations
Approach to calculations for The Calibration Curve. For the standard solutions, the number of moles of
SCN–
is much greater than the number of moles of Fe3+
. Using LeChatelier’s Principle, the excess SCN–
drives reaction (1) to completion (or >99% of the way to completion). Therefore, for the standard solutions
used to prepare the calibration curve, Fe3+
is the limiting reactant and the initial concentration (accounting
for dilution to 10 mL) of Fe3+
is converted entirely to FeSCN2+
.
Approach to calculations for Determination of the Equilibrium Constant. For these solutions, the
number of moles of Fe3+
is approximately equal to the number of moles of SCN–
. In this case, we will
observe that the reaction does not go to completion. When a reaction does not go to completion, we can
count on setting up some kind of ICE table. The ICE tables and the equilibrium values of the concentrations
will allow us to determine the value for Kc, the equilibrium constant. Ideally, all of our calculations will
lead to similar values of Kc.
A. Calculating the concentration of a diluted solution.
This calculation will be used any time you mix solutions together to calculate the concentration of ions in
the new solution.
Ex: If 0.100 mL of 2.00×10–3
M SCN–
is diluted to a volume of 10.00 mL, what is the final
concentration of SCN–
ion?
M1V1 = M2V2
(2.00×10–3
M) (0.100 mL) = M2 (10.00 mL)
M2 = 2.00×10–5
M
Units on concentration and volume can be any units, as long as they cancel out.
B. Determining “conc. of FeSCN2+
final, (M)” for Table 4 from the calibration curve
In Table 2, there are five absorbance values. These absorbance values represent the absorbance of
FeSCN2+
. The calibration curve represents the relationship between conc. of FeSCN2+
and
7. 9
absorbance of FeSCN2+
. First, use Excel to find the equation of the line (y = mx + b) that relates
conc. (x) to absorbance (y). Then, use the absorbance values to plug into this equation and solve
for conc. Remember, it is impossible for the conc. of FeSCN2+
to be greater then the initial conc.
of either reacting species.
C. Calculating the value of the equilibrium constant from data in Table 2.
Suppose that [Fe3+
] = 8.0×10–4
M, [SCN–
] = 8.0×10–5
M, and that you determine from your
calibration curve that [FeSCN2+
] = 3.0×10–5
M. At this point, your MICE table looks like this:
M Fe3+
(aq) + SCN–
(aq) ↔ FeSCN2+
(aq)
I 8.0×10–4
8.0×10–5
0
C
E 3.0×10–5
From the three columns in Table 4, there is enough information to determine the value of Kc.
Because we know the initial concentration (we start with none) and the equilibrium concentration
of FeSCN2+
(we do assume that the reaction is at equilibrium by the time we get it into the
spectrophotometer, but this is a very good assumption born out by the fact that we don’t see the
color of the solutions changing with time), we can figure out the change in concentration of
FeSCN2+
. Since the change must be the same for all of them (taking into account coefficients), we
can fill in our table to make it look like this:
M Fe3+
(aq) + SCN–
(aq) ↔ FeSCN2+
(aq)
I 8.0 10–4
8.0 10–5
0
C –3.0×10–5
–3.0×10–5
+3.0×10–5
E 7.7×10–4
5.0×10–5
3.0 10–5
From here, we need to use the Kc expression for reaction (1) to get the value of Kc for this
reaction. Because reaction (1) forms complex ion FeSCN2+
, it is also called Kf (even though it
follows all the same rules as any Kc).
IV. Formatting Your Lab Notebook
A. Experiment title, date, your name and name of your partner. Page numbers for each page.
B. Introduction
1. What is the purpose of this lab?
2. Why does the reaction go to completion in Procedure 1 but not go to completion in Procedure 3
even though the value of Kc is constant in both procedures.
3. Handwritten procedure with spaces left open for each measurement and data table. Data tables
may be cut out and taped into the lab notebook or recreated by hand.
C. In Class Work
1. All data, averages and standard deviations must be calculated.
2. Hand-drawn plot of the calibration curve that takes up at least half a page in the notebook. If
your notebook does not have graph paper in it, then obtain a piece of graph paper from the
instructor, draw the graph on the paper and tape or staple the graph into your lab notebook.
D. Experimental Summary: in notebook before you leave lab
Were there any data points that had to be thrown out? Was your calibration curve linear?
8. 10
E. Results: at home
1. Calibration curve prepared by computer with best-fit line and R2
value displayed on graph.
Instructions on how to do this can be found in the introductory handout labeled “How to plot in
Excel.”
2. Calculations to determine [FeSCN2+
] in the unknown solutions.
3. ICE tables with Kc values for each of the 5 data points from Procedure 3.
4. Average and standard deviation values for Kc.
F. Experimental Summary: after all calculations are complete
Given that we don’t know the correct value of Kc for this experiment, and therefore can’t say
anything about accuracy, using standard deviation to assess precision how precise were your
values of Kc?
1
http://www.chem.vt.edu/chem-ed/spec/uv-vis/singlebeam.html accessed 8/12/05