5. For the titration of 50.00 mL of 0.0500 M Ce4+ with 0.1000 M Fe2+ in the presence of 1 M H2SO4, please calculate the system potential while 3.00 mL of Fe2+ is added.
Ce4+ + e <==> Ce3+, E0 = + 1.44 V (in 1 M H2SO4)
Fe3+ + e <==> Fe2+, E0 = + 0.68 V (in 1 M H2SO4).
Answer is 1.49 V
5b) In the above titration, what's the electrode potential after 28.90 mL of Fe2+ is added?
Answer is 0.73 V.
Just wondering, how they got that?
In: Chemistry
1,All of the following are true concerning nuclear fission except
a) Uranium is typically split into smaller atoms
b) Nuclear reactors are used to make electricity
c) The energy involved can be calculated using E = mc2
d) The reaction involved is called a thermonuclear reaction
e) During fission there is a change in mass called the mass defect
2,
All of the following are true concerning nuclear fusion except
| a)Typically hydrogen is fused together to form helium | |
| b) The amount of hydrogen needed to achieve this is called the critical mass | |
| c) At this time there have been no economically successful fusion reactors created | |
| d )Fusion requires extremely high temperatures | |
| e) Nuclear fusion is the process that powers the sun |
In: Chemistry
Which of the following salts would be more soluble in acid solution than in pure water?
PbBr2
AgNO3
SrCl2
AgI
Please provide a thorough explanation as I was absent during this lecture... Thank you!!
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Name the complex ion [Cu(NH3)2(H2O)4]2+. The oxidation number of copper is +2.
In: Chemistry
Phenolphthalein was the indicator you used in your titration.
a. What made phenolphthalein a good choice of indicator? (Meaning, how do you choose an appropriate indicator for a titration.)
b.You used only a couple drops of a 1% solution. Why is it important to use such a small quantity of indicator in a titration?
c.The point where the color changed is known as the end point. What is the difference between the end point and equivalence point?
d.Can the end point be used quantitatively? Why or why not?
In: Chemistry
At T=Tc, (∂P/∂V)V T=Tc = 0 and (∂2P/∂V2)T=TC = 0. Use this information to derive expressions for a and b in the van der Waals equation of state in terms of experimentally determined Pc and Tc.
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A chemical process stream enters a shell-and-tube exchanger at a temperature of 200 °F and does two passes on the shell side, exiting the exchanger at 170 °F. For this particulate scenario, the heat exchanger has 200 stainless steel tubes that are 2-in. OD and 10 ft long. Indicate whether the temperature of the process stream will increase, decrease, or remain the same under the following scenarios. Justify your answer. a) The flow rate of the cooling fluid is increased. b) There are 100 tubes that are 1.5-in. OD and 26.6 ft long. c) The number of shell passes is doubled. d) The tube material is changed to copper.
In: Chemistry
1. Ka for hydrocyanic acid, HCN, is 4.00×10-10. Ka for acetylsalicylic acid (aspirin), HC9H7O4, is 3.00×10-4. Ka for phenol (a weak acid), C6H5OH, is 1.00×10-10
| What is the formula for the strongest acid? |
2. Ka for nitrous acid, HNO2, is 4.50×10-4. Ka for hydrocyanic acid, HCN, is 4.00×10-10. Ka for phenol (a weak acid), C6H5OH, is 1.00×10-10.
| What is the formula for the strongest conjugate base? |
3. The compound ammonia , NH3, is a weak base when dissolved in water. Write the Kb expression for the weak base equilibrium that occurs in an aqueous solution of ammonia :
4. Write the Ka expression for an aqueous solution of acetic acid , CH3COOH :
In: Chemistry
2. Outline essential structural features a 1,4-Dihydropyridine must possess for effective Ca2+ channel blocking capability. Why are dimethyl 1,4-Dihydro-2,6-Dimethylpyridine-3,5-Dicarboxylate and diethyl 1,4-Dihydro-2,6-Dimethylpyridine-3,5-Dicarboxylate ineffective in this regard?
In: Chemistry
Part III (Plus answers to questions posted in the laboratory manual):
i) What are Q, [Ag+(aq)anode], and [Ag+(aq)cathode] when Emeasured becomes 0 mV for a concentration cell prepared from half cells having initial concentrations of 1.0 and 0.01 M. respectively?
ii) Assuming that both solution volumes were 10.0 mL for the concentration cell described in the above question, how much electricity (in coulombs) flowed from the time the circuit was completed until equilibrium was established?
In: Chemistry
Calculate the volume, in milliliters, of a 0.216 M NaOH solution that will completely neutralize each of the following: 1.) 3.71 mL of a 1.32 M HNO3 solution. 2.) 8.10 mL of a 0.800 M H3PO4 solution.
In: Chemistry
In: Chemistry
Complete combustion of 7.70 g of a hydrocarbon produced 23.6 g of CO2 and 11.3 g of H2O. What is the empirical formula for the hydrocarbon? Insert the subscripts:
CH
In: Chemistry
a) The reaction temperature for this lab is significantly above the boiling point of the solvent used (ethanol boils at 78 o C; the reaction mixture was heated up to 140 o C). Why are we able to conduct reactions above the boiling point of the solvent when using our microwave oven in lab?
b) Explain why hexane is a very poor choice as a solvent for a microwave reaction.
c) After developing a TLC plate, a student looks at the TLC plate under the UV lamp but cannot see any spots. What could the student have possibly done wrong? List three separate possible reasons for not being able to see any spots on a developed TLC plate.
d) After developing a TLC plate, a student looks at the TLC plate under the UV lamp but only sees large, overlapping blobs, instead of small spots. What is the likely problem, and what should the student do to obtain a better TLC?
In: Chemistry
The pKb values for the dibasic base B are pKb1 = 2.10 and pKb2 = 7.53. Calculate the pH at each of the following points in the titration of 50.0 mL of a 0.75 M B(aq) with 0.75 M HCl(aq).
(a) before addition of any HCl
(b) after addition of 25.0 mL of HCl
(c) after addition of 50.0 mL of HCl
(d) after addition of 75.0 mL of HCl
(e) after addition of 100.0 mL of HCl
In: Chemistry