Hey there! My professor wrote this vague problem on the board and I can't figure out how to solve it so --- I apologize in advance for any lack of clarity.

50.0 mL of 0.03M of Cysteine is titrated by 0.06M of NaOH

pKa 2= 8.37

pKa 1 = 1.92

What is the pH of the solution.....

1) Before any titrant is added

2) 12.5 mL of NaOH

3) 25.0 mL of NaOH

4) 37.5 mL of NaOH

5) 50.0 mL of NaOH

6) 60.0 mL of NaOH

I really want to understand this type of problem for exams in the future so any explanation to go along with your work would be super appreciated. Thank you!!

The patient is a 24 year-old truck driver who recently drove across the country, was admitted to the hospital because of shortness of breath (dyspnea) and chest pain. Her dyspnea began suddenly three hours before admission. It was associated with chest pain that the patient described as feeling "like a knife stabbing me in the chest when I breathe in." She also had right leg pain in her popliteal fossa (the slight depression on the back side of the knee). Physical Examination revealed an anxious-appearing female in obvious respiratory distress.

Temperature: 100 degrees F
Pulse: 90
Respirations: 28
Blood pressure: 100/60
Skin: No cyanosis
Lungs: Inspiratory rales (crackling sounds) heard over the right base
Legs: Tenderness and erythema (redness) over the right popliteal fossa; mild edema of the right leg from the knee down.
Arterial blood gases:

pH of 7.48,            (normal   7.35-7.45 )

pO2 of 70 mmHg. (normal pO2 90-100 mmHg)

pCO2 of 30 mmHg.            (normal pCO2 35-45 mmHg)

One possible diagnosis for the patient is a pulmonary embolus.

The patient was placed on intravenous heparin and then began oral Coumadin during her weeklong hospital stay. Both drugs are anticoagulants which prevent enlargements of blood clots and allow the body's normal clot-dissolving pathways to work. The patient was sent home with a prescription for Coumadin, and advised to avoid factors that promote blood clotting, such as smoking, oral contraceptives, and prolonged inactivity (such as driving for long periods without breaks). The patient was able to stop taking Coumadin after six months.

Answer the following questions:

1. How are ventilation and perfusion affected in a pulmonary embolus?    Circle one:   A or B

A. Reduced pulmonary ventilation, excessive perfusion             B. Alveolar ventilation is the same, inadequate perfusion

2. The patient was found to have a blood clot in her right popliteal vein. List 3 major blood vessels that an embolus from here would pass through on the way to the right lung. (3 pt)

R. popliteal vein           à ___________________________________________ (limb) à

_______________________________________________ (abdomen) à

_______________________________________________ (thorax)     à right lung

3. Where would a pulmonary embolus most likely lodge, causing the patient’s symptoms? [Hint: a blood vessel from question 2 above, based on patient’s symptoms].

4. Interpret the patient’s arterial blood gas results: pH of 7.48, pO2 of 70, pCO2 of 30 mmHg (see normal blood arterial gas results). How would you classify this patient’s acid-base status? Discuss in terms of arterial pH, arterial blood pO2 and pCO2. [Hint: Textbook 23.6 Effect of O2 and CO2 pressure gradients]

5. Give the importance of buffers. Name at least two substances that act as buffers.

The equilibrium constant, K, for the following reaction is

1.29×10-2 at 600 K. COCl2(g) CO(g) + Cl2(g)

An equilibrium mixture of the three gases in a 1.00 L flask at 600 K contains 0.315 M COCl2, 6.38×10-2 M CO and 6.38×10-2 M Cl2. What will be the concentrations of the three gases once equilibrium has been reestablished, if 3.31×10-2 mol of Cl2(g) is added to the flask?

[COCl2] =____ M [CO] =____ M [Cl2] = ____M

draw the lewis structure for CH3CHBrCHBrCH2CH3 and for CH3CHFCH2OH

Circle the group in each pair below that has the highest priority using the Cahn-Ingold-Prelog system

-CH3 or -CBr3

-CH2CBr3 or -CHBrCH3

-CH=CH2 or -CH2CH3

Q1: Write the balanced molecular reaction and the net ionic reaction for the reaction between BaCl2 and Na3PO4 in aqueous solution: Molecular reaction:

____BaCl2(aq) + ____Na3PO4(aq) → ____ ___________ + ____ __________

Net ionic reaction:

Q2: Classify the following reactions as: acid-base, precipitation, combustion, combination, and displacement or disproportionation reaction:

BaCl2(aq) + MgSO4(aq) → BaSO4(s) + MgCl2(aq) __________________________ reaction

NH3(aq) + HBr(aq) → NH4Br(aq) _______________________________

reaction 2CO(g) + O2 → 2CO2(g) _______________________________ reaction

Q3: Circle the correct answer for each

            CO3^2– is a                    Brønsted acid / Brønsted base / can be both

            HCO3^– is a                  Brønsted acid / Brønsted base / can be both

            PO4^3– is a                    Brønsted acid / Brønsted base / can be both

            H3PO4 is a                   Brønsted acid / Brønsted base / can be both

            H2PO4^– is a                 Brønsted acid / Brønsted base / can be both

            CH3COOH is a           Brønsted acid / Brønsted base / can be both

            CH3COO^– is a             Brønsted acid / Brønsted base / can be both

            SO4^2– is a                     Brønsted acid / Brønsted base / can be both

Q4: The oxidation numbers of S in SO3^2– and,SO4^2– are:

A. +2 and + 4              B. +3 and +6               C. +4 and +6               D. +6 and +8               E. –4 and –6

Q5: The oxidation number of Cr in the dichromate ion, Cr2O7^2– is:

A. +6                           B. +5                           C. +4                           D. –4                           E. +7

Q6 For which of the following pairs are both compounds insoluble in water?

A.NaBr, Na2SO4

B. Na2CO3, CaCO3  

C. Fe2(CO3)3, Ba3(PO4)2

D. Na3PO4, Ca3(PO4)2

E. PbSO4, MgSO4

In a stereospecific wittig reaction: Discuss the betaine intermediate of the Wittig reaction and why the stereochemistry of the intermediate determines the stereochemistry of the alkene product.

Suppose you need to prepare 1.0 L of Stock solution which must have a concentration of 150 mg N/L. You start with solid Potassium Nitrate, KNO₃ .

A. How many moles of Nitrogen should 1.0 L of Stock solution contain?

B. How many moles of KNO₃ should 1.0 L of stock solution contain?

C. How many grams of KNO₃ will you have to weigh out to prepare 1.0 L of stock solution? (Show ALL work!) (Reminder: the concentration of stock must be known to 3 significant figures!)

2. Another Stock solution you may have to prepare must contain 80.0 mg Phosphorus /L. Using steps similar to those used for Nitrogen Stock solution in Question 1, find how many grams of Potassuim Dihydrogen Phosphate (KH₂PO₄ ) you will need to weigh out to prepare 1.0 L of such Stock solution

Using benzene or toluene as the only aromatic organic starting material, devise a synthesis for each of the following:

a. o-chlorotoluene

b. 3-bromonitrobenzene

c. p-toluenesulfonic acid

d. 2-chloronitrobenzene

Synthesis of banana oil

this is my discussion and below it is the professors comments. Can you correct it for me?

Discussion:

            The purpose of the experiment performed was to synthesize isopentyl acetate, or more commonly known as banana oil, from isopentyl alcohol and glacial acetic acid. Both liquids were combined and remained clear until the addition of concentrated sulfuric acid. The addition of an acid caused a reaction to occur that resulted in a polymer, which gave the mixture color. The liquid turned dark brown when the polymer formed. The polymer was removed via distillation.

            After creating the ester, the biggest challenge was separating it from all the other chemicals in the flask, which include water, acetic acid, sulfuric acid, and isopentyl alcohol. The isopentyl acetate is not soluble in water; so two layers are created in the separatory funnel. While the product will not dissolve in water, both acetic acid and sulfuric acid are. Since the acids are also slightly in the organic layer, sodium bicarbonate is used to convert the acids into a salt, which is soluble in water, as seen in Figure 2. The sodium bicarbonate reaction also produces carbonic acid, which is unstable and will break down into water and CO₂ as seen in Figure 3. The little amount of unreacted isopentyl alcohol is separated by removing the first ten drops of product during the distillation. This is possible because it has a lower boiling point then the ester that is produced.

            This whole reaction was first done and called the Fischer esterification. The general reaction scheme can be seen above. In the experiment, isopentyl alcohol and acetic acid react in the presence of sulfuric acid to form isopentyl acetate. This reaction mechanism can be seen below in Figure 5.

Figure 5 – Fischer esterification mechanism

In the reaction above, Acetic acid takes a proton from concentrated sulfuric acid. Then it reacts with isopropentyl alcohol. Delocalization of electrons and protons in later steps leads to elimination of water molecule to form final product.

            During the distillation, the temperature was recorded for the boiling point of isopentyl acetate. It was found to be at 129 degrees Celsius. This is low compared to the literature value of 142 degrees Celsius. This difference is believed to be due to the different typed of thermometers used to record the boiling point. The literature value most likely used a mercury thermometer, while the experiment performed used an alcohol thermometer. Alcohol thermometers are not as accurate as mercury thermometers, but have to be used due a law banning mercury thermometers in the state of New Jersey. Because of this, not much can be said about the purity of the substance obtained.

            While an NMR was not taking during the experiment, nor was an IR spectrum, attached is both an NMR example and an IR example of isopentyl acetate. On the NMR sheet, all hydrogen peaks are labeled on a drawing of the molecule, and all the information is written in the chart. On the IR sheet, peaks above 1500 cm^-1 are labeled for what they are believed to be. While the pictures were found from a reputable source, they were not from the experiment performed so one cannot be perfectly sure that the desired substance was obtained.

            The last topic for the reaction was the product loss. Most organic reactions are not perfect and have relatively low yields. The 42 percent yield was most likely due to side reactions occurring in the flask. Since there were several chemicals in the flask together, side reactions are bound to occur, creating a lower yield. For example, a polymer was formed which changed the color of the flask. This was not intended to happen so this reaction lowered the yield of the experiment.

professors comments.

You need to explain what substances should have been in the flask at the end of refluxing. Show a flow

diagram of the purification process. You did an extraction, a drying and a distillation.

Alcohol thermometers are quite accurate in the range they are designed to function. This type of

alcohol thermometer was not designed to work around 142 degrees C.

Treat the NMR and IR spectra as if they were obtained by you for your product. You should have tables

in your Results Section for IR, NMR and GC. You should discuss these results in more detail in the

discussion. What do we learn from each measurement.

Give more details of the many causes for obtaining less than 100% Yield.

Discuss whether this experiment is a good example of Green Chemistry. Does the Atom efficiency make

it a good candidate. Does the Reaction efficiency make it a good example of Green chemistry. What

about other things.

Balance the following redox reaction if it occurs in H₂SO₄. What are the coefficients in front of H₂O and Cr₂(SO₄)₃ in the balanced reaction?

C₃H₈O₂(aq) + K₂Cr₂O₇(aq) → C₃H₄O₄(aq) + Cr₂(SO₄)₃(aq)

Can someone please explain everything step by step since how to determine oxidation numbers and half reactions?

In an acid base titration experiment, 50.0 ml of a 0.0500 m solution of acetic acid ( ka =7.5 x 10^-5) was titrated with a 0.0500 M solution of NaOH at 25 C. The system will acquire this pH after addition of 20.00 mL of the titrant:

Answer is 4.581

Please show all work

A 10.00 mL solution of 0.0500 M AgNO3 was titrated with 0.0250 M NaBr in the cell: S.C.E.(saturated calomel electrode) titration solution Ag (s). (Ksp AgBr(s) = 5.0e-13)

Find the cell voltage (v) when the volume of titrant added is 5.00 ml.

Find the equivalence volume (ml) of titrant added.

Calculate the cell voltage (v) when the volume of titrant added is 24.58 ml

Calculate the cell voltage (v) at the equivalence point.

.

A student aims to perform a titration to determine the exact concentration of HNO3. The bottle was labeled with only an approximation concentration of 0.5 M. In order to ensure accuracy the volume of the titrant used should be half the 50.0 mL capacity of the burette. The student decides the analyte volume will be 20.0 mL and the titrant will be NaOH. The student sets out to determine the concentration of NaOH needed and the mass required to prepare 1.00 L of titrant. Fill in the missing information to 2 significant figure. The student determines that the concentration of the NaOH solution should be _________ and the mass of NaOH required to prepare 1.00 L of this solution is __________.

Determine the bond orders for the following species: S₂^2-, S₂^-, S₂, S₂⁺, S₂²⁺.