Finding Keq

CJ Artates, Tyler Lange, Xavier Cornelius

Part I:  Preparation of a standard absorption curve for FeSCN+2

Standard 0.20M Fe(NO3)3 0.0020 M KSCN 0.100M HNO3 [FeSCN+2] Absorbance
A

 

10.0 mL 0.0 mL 15.0 mL  0.0 M  0.00
B

 

10.0 mL 1.0 mL 14.0 mL  8.0 x 10^-5  0.39
C

 

10.0 mL 1.5 mL 13.5 mL  1.2 x 10^-4  0.50
D

 

10.0 mL 2.0 mL 13.0 mL  1.6 x 10^-4  0.56
E

 

10.0 mL 2.5 mL 12.5 mL  2.0 x 10^-4  0.79
F

 

10.0 mL 3.0 mL 12.0 mL  2.4 x 10^-4  1.03

EQUATION:       y = 4017.9x + 0.0093                                                              R2 = 0.974

Part 2: Measuring Equilibrium

Test Solution 0.0020 M Fe(NO3)3 0.0020 M

KSCN

0.10 M

HNO3

Initial [Fe+3] Initial [SCN] Absorbance Equilibrium

[FeSCN+2]*

I

 

5.0 mL 0 5.0 mL  0.001  0  0.00
II

 

5.0 mL 1.0 mL 4.0 mL  0.001  0.0002  0.16  3.6 x 10^-5
III

 

5.0 mL 2.0 mL 3.0 mL  0.001  0.0004  0.34  8.2 x 10^-5
IV

 

5.0 mL 3.0 mL 2.0 mL  0.001  0.0006  0.52  1.3 x 10^-4
V

 

5.0 mL 4.0 mL 1.0 mL  0.001  0.0008  0.91  2.2 x 10^-4
VI

 

5.0 mL 5.0 mL 0.0 mL  0.001  0.001  1.04  2.6 x 10^-4

 

* To be determined from the standard graph equation.

ANALYSIS:

Use your graph equation to calculate the equilibrium concentrations of FeSCN+2.

  1.  Prepare and ICE chart for each test solution (II – VI) and calculate the value of Keq for each of your 5 tests solutions.

ICE CHARTS

Test Solution

Keq = 2.30 x 10^2

Fe3+               +                SCN–                    ⇄            FeSCN2+
I

 

0.001  0.0002  0
C

 

 – 3.6 x 10^-5  – 3.6 x 10^-5  + 3.6 x 10^-5
E

 

 9.64 x 10^-4  1.64 x 10^-4  3.64 x 10^-5

 

Test Solution

Keq = 2.81 x 10^2

Fe3+               +                SCN–                    ⇄            FeSCN2+
I

 

0.001  0.0004  0
C

 

 -8.2 x 10^-5  -8.2 x 10^-5  + 8.2 x 10^-5
E

 

 9.18 x 10^-4  3.18 x 10^-4  8.2 x 10^-5

 

Test Solution

Keq = 3.18 x 10^2

Fe3+               +                SCN–                    ⇄            FeSCN2+
I

 

0.001  0.0006  0
C

 

 -1.3 x 10^-4  -1.3 x 10^-4  +1.3 x 10^-4
E

 

 8.70 x 10^-4  4.70 x 10^-4  1.3 x 10^-4

 

Test Solution

Keq = 4.86 x 10^2

Fe3+               +                SCN–                    ⇄            FeSCN2+
I

 

0.001  0.0008  0
C

 

 -2.2 x 10^-4  -2.2 x 10^-4 + 2.2 x 10^-4
E

 

 7.80 x 10^-4  5.80 x 10^-4  2.2 x 10^-4

 

Test Solution

Keq = 4.75 x 10^2

Fe3+               +                SCN–                    ⇄            FeSCN2+
I

 

0.001  0.001  0
C

 

 -2.6 x 10^-4  -2.6 x 10^-4 + 2.6 x 10^-4
E

 

 7.40 x 10^-4  7.40 x 10^-4  2.6 x 10^-4

Comment on your Keq values.   Do your results convince you that Keq is a constant value regardless of the initial concentrations of the reactants?  Why or why not? CONCLUSION AND EVALUATION:

Keq is constant. Our average value recorded from our data wasn’t very far off from the reported value of Keq. If we had done the lab more precisely, our Keq values for each solution would be the same. We had some possible cross contamination with each solution that might’ve affected our average Keq.

  1. Calculate the average value of Keq from your five trials. The actual value of Keq  for this reaction at 25oC is reported as 280.   Calculate (should you use all of your values?) the percent difference of your average value from the reported value:

% difference = (experimental value – reported value) x 100%

(358 – 280)/280 x 100% = 28% Error

Reported value

Poetry Pairings: A Flame

Link Here

in this article, Trymaine Lee relives receiving an unexpected heart attack after the age of 38 and how not only his life, but his family’s life had take a turn. This article first caught my attention because I personally know this experience all too well. Last September my Father had also received an surprise heart attack almost killing him. Lee walks us trough his pain and struggle, not only the literal, physical pain, but the pain of having to say goodbye to those he cherishes. The poem “The Wisp”, goes over the theme of triumph, although the connection may not “click” to the reader right away I believe that Lee really did come out triumphantly over a great battle. He “hit the lottery” (Lee), and that is something he should celebrate.

“A heart attack either kills you or it doesn’t.
I spent the better part of 16 years reporting stories that led me to people who had just missed death. Who understood, better than anyone else, what it is like to make a narrow escape. Ms. Fuller was 19 when I met her, more than a dozen years removed from the bullet. Since the heart attack, I’ve been thinking about what she told me. That it’s important not to be numb. It’s important to say: I could have died.
I didn’t. I have tomorrow, or at least this moment. I want to live.” (Lee)

I believe this image fits with the metaphor of a flame as the sky also compliments the imagery of a bird soaring.

The Wisp

What is Triumph?

triumph rips into my soul,
and settles down to the brilliant candle that lights the path to an endless tunnel. Flickering. Possibly, that flame transforms into a hopeless wisp of ash.

What is Triumph?

It is the sun caressing your face at the highest point of dawn
When the birds soar through heaven and tickle the clouds

What is Triumph?

It is the lion on the highest peak roaring throughout its kingdom, making his presence known to all

What is Triumph?

It is the rebirth of that courageous ember that burns in the deepest of seas

Pass It On

Allison is aware that by just walking, she is not solving racism but she does believe that by taking her own privilege away she is helping the problem of racism in her own small way. She walks with her groceries in the rain to equal herself to her neighbors who haven’t had the same opportunities. Allison did eventually receive a ride in the man’s car, however she instantly felt guilt as she realized she had done what she had been against. This is quite similar to the quote by Gandalf, with the evil being the racism, Allison being the “ordinary folk”, and her walking the act of kindness. In today’s society, an act of love and kindness could be as simple as holding a door open for someone or giving up your seat on the bus for the elderly. I have also found this similar to Colin Kaepernick, although he is not an ordinary man, his action of kneeling during the American national anthem has become a staple to todays activists. His actions are proof that repetition of a gesture may rub off on others.

An Infamous Relationship

Link to article

From his clothing style to his music Kanye west has always been someone who I’ve been interested in. this interest is what brought me towards this article. In a very short summary, this writer talks about the infamous relationship between the 21 Grammy awarded artist and questionably the most controversial American president of all-time Donald Trump. I found this article insightful as it helped me to realize the importance of their relationship to each other, as it is beneficial to both of their careers. West uses Trump as a sign of wealth in his lyrics, while Trump uses West as a illusion to make it seem like celebrities like him and his beliefs. However, with this topic I do not agree with anything Trump has said since entering politics but I also do not agree with those who decide to boycott West just strictly based on his own politic views as somebody not even in politics itself. Although due to this relationship I am sure I am not person who may be interest to see the day when Kanye West may run against the current president.

An Upset In Sports History

Link to article

Although I would not consider myself a fan of tennis at all I do pay attention to news of huge sporting events. However not only did the sporting event make headlines for the game itself but for the controversy that followed it. In this years U.S. Open the famous and favoured to win Serena Williams, ironically fought hard to no surprise but came short in the final moments of the game leaving a young Naomi Osaka the victor of the tournament. This upset was news but not for the reason others may expect. What drew the attention of others to this game was serena Williams behavior during the game. She was penalized during her match, later accusing the umpire of being sexist. This lead to illustrator for The Herald Sun, Mark Knight to create an image of the match for this newspaper. In this image Williams is drawn similar to an ape throwing a temper tantrum while Osaka, who is of Japanese and Haitian, is shown as a whitewashed blonde. This is not a good look for the illustrator or the paper due to resorting to stereotypical drawings. However as a world famous athlete I do believe it should come to no surprise that the media may not always depict you as how you want to be seen. With all this news surrounding this match I find it has unfairly taken away the attention to Osaka that she deserves, defeating a notable player who is considered an all-time great and now being crowded a champion.

Neuron Communication

NEURONS

The function of a neuron depends on the type of neuron, each having its own function. The first neuron is the interneuron or relay neuron (white and green). The job of this nerve cell is to communicate with the sensory and motor neuron. With the sensory neuron (black) the function of this nerve cell is to convert external stimuli from the environment into internal electrical impulses which are sent to the brain. From here the interneurons in the brain make a decision, finally sending impulses to the motor neurons (pink and green) to make a certain motion. This process can be demonstrated using a coffee shop as an example. You are at a coffee shop and you are waiting for your order. Using your sensory neurons, you see your drink is finished being made and the barista hands you the drink, your sight enables you to sense this. You make a decision of what to do with the coffee with you interneurons, lastly you pick up the coffee with your hands after your brain makes the decision to do so after sending impulses through your motor neurons.

 

ACTION POTENTIAL

Action potential is an electrochemical signal that briefly travels throughout the axon. This is caused by positive sodium ions and negative potassium ions making movement within the axon. In polarization of action potential, it is constant with positive ions on the outside of the axon and negative ions on the inside. In depolarization, the positive ion enter the axon through channels in the membrane. Once entered a new channel opens for the positive potassium ions to leave the axon. This process is called repolarization.

SYNAPSE

Once the action potential (AP) reaches the end of the neuron’s axon, synapse occurs. A signal is sent to from one neuron to another. This signal travels from the axon of one neuron to the dendrite of the neuron that is receiving the signal. The synaptic vesicles in the axon produce neurotransmitters (NT) which are then released into the synaptic gap. This is when the released NT bind with the receptors on the dendrites of the receiving neuron. These NT can either stimulates the AP by being excitatory or can repress the AP by being inhibitory, ultimately this is decided by the receptor. If the NT is glutamate it would causes an excitatory reaction and stimulate the AP where as if the NT is GABA it would cause the opposite and repress the AP with an inhibitory reaction.

synapse photo link:https://www.quora.com/What-happens-at-synapse