Name the complex ion [Cu(NH3)2(H2O)4]2+. The oxidation number of copper is +2.

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?

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.

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.

1. K_a for hydrocyanic acid, HCN, is 4.00×10^-10.  K_a for acetylsalicylic acid (aspirin), HC₉H₇O₄, is 3.00×10^-4. K_a for phenol (a weak acid), C₆H₅OH, is 1.00×10^-10

2. K_a for nitrous acid, HNO₂, is 4.50×10^-4. K_a for hydrocyanic acid, HCN, is 4.00×10^-10. K_a for phenol (a weak acid), C₆H₅OH, is 1.00×10^-10.

3. The compound ammonia , NH₃, is a weak base when dissolved in water. Write the K_b expression for the weak base equilibrium that occurs in an aqueous solution of ammonia :

4. Write the K_a expression for an aqueous solution of acetic acid , CH₃COOH :

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?

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?

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.

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

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?

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

500.0 mL of 0.140 M NaOH is added to 565 mL of 0.250 M weak acid (Ka = 8.39 × 10-5). What is the pH of the resulting buffer?

HA(aq)+OH^-(aq)=H2O(l)+ A^-(aq)

pH=?

The following takes place in a voltaic cell:
Zn(s) + Cu2+(1 M) → Cu(s) + Zn2+(1 M).
The cell has a voltage of +1.10 V.
Choose the answer that best relates to
questions 1-4.
(A) there is no change in the voltage
(B) the voltage becomes zero
(C) the voltage increases
(D) the voltage decreases, but stays
positive
(E) the voltage becomes negative
1. What happens to the voltage when a
saturated ZnSO4 solution is added to
the zinc compartment of the cell?
2. What happens to the cell voltage
when the copper electrode is made
smaller?
3. What happens to the cell voltage
when the salt bridge is filled with
deionized water instead of 1 M
KNO3?
4. What happens to the cell voltage
after the cell has operated for 10
minutes?

Could you please explain why?

A 500 mL buffer is usually prepared with 46 mM carbonic acid and 58 mM sodium bicarbonate. Unfortunately you have run out of these reagents; on hand you have the following: solid citric acid, disodium maleate (salt of maleic acid), benzylamine and hydrochloric acid. Which reagent(s), and how much of each, would you need to use to produce a 500 mL buffer with the same formal concentration and pH as the carbonic acid buffer

I calculated the original pH of the solution to be 6.452 and the original amount of moles to be 0.052.

What I'm stuck on is how to properly make a buffer without a strong conjugate for the colution