Kinetic Study of an Iodine Clock Reaction.

Flask A contains 5.00 mL of 6 M HCl (density 1.11 g/mL). Flask B contains 5.00 mL of the same 6M HCl solution used in flask A, 2.00 mL of ethyl acetate (density 0.893 g/mL), and 3.00 mL of water (density 1.00 g/mL). Flask A was titrated with 1.00 M NaOH, and it required 31.95 mL to reach a phenolphthalein end point. Flask B was sealed and allowed to sit for 7 days to allow the system to reach equilibrium. At the end of the 7 day period, flask B was titrated with 1.00 M NaOH, and it required 42.75 mL of NaOH solution to reach a phenolphthalein end point.
Using the information above answer the following questions for the system outlined below.
ethyl acetate + water <--> ethyl alcohol + acetic acid

1-Based on the titration information for flask A, determine the number of moles of HCl in 5.00 mL of the 6 M HCl solution used for the experiment. Note that the concentration of the HCl solution is approximately 6M, and the actual concentration may be slightly higher or lower. Do not include units in your answer.

2-Calculate the moles of water in a 5.00 sample of the 6M HCl solution used for the experiment. Do not include units in your answer.

3-Determine the initial moles of water in flask B immediately after mixing. Do not include units in your answer.

4-Determine the initial moles of ethyl acetate in flask B immediately after mixing. Do not include units with your answer.

5-Determine the moles of acetic acid in flask B at equilibrium based on the titration data for flask B. Note that the HCl that was added to the flask is still present at equilibrium. Do not include units in your answer.

6-Using the moles of acetic acid at equilibrium, the stoichiometry of the reaction, and the initial number of moles of water, determine the moles of water at equilibrium. Do not include units with your answer.

7-Using the moles of acetic acid at equilibrium, the stoichiometry of the reaction, and the initial number of moles of ethyl acetate, determine the moles of ethyl acetate at equilibrium. Do not include units with your answer.

8-Calculate the equilibrium constant for the system.

The value of Ka in water at 25 °C for propionic acid (C2H5CO2H) is 3.4 x 10-5 M. What is the pH of a 0.020 M aqueous solution of propionic acid?

how the leaving group affect the behavior of the alkyl halide in mixture of NaI/ Acetone and in mixture of AgNO3/ Ethanol?

2. Buffer capacity refers to the amount of acid or base a buffer can “absorb” without a significant pH change. It is governed by the concentrations of the conjugate acid and base forms of the buffer. A 0.5 M buffer will require five times as much acid or base as a 0.1 M buffer for given pH change. In this problem you begin with a buffer of known pH and concentration and calculate the new pH after a particular quantity of acid or base is added. In the laboratory you will carry out some stepwise additions of acid or base and measure the resulting pH values.

Starting with 60 mL of 0.50 M phosphate buffer, pH=6.83, you add 1.7 mL of 1.00 M HCl. Using the Henderson-Hasselbalch equation with pK2 for phosphate of 6.64 calculate the following values to complete the ICE table.

What is the composition of the buffer to begin with, both in terms of the concentration and the molar quantity of the two major phosphate species? (Units required.)

What is the molar quantity of H3O+ added as HCl, and final molar quantity of HPO and H2PO4- at equilibrium?

What is the new HPO42-/H2PO4- ratio, and the new pH of the solution?(Note: you can use the molar ratio rather than the concentration ratio because both species are in the same volume.)

Now take another 60 mL of the 0.50 M pH 6.83 buffer and add 3.7 mL of 1.00 M NaOH. Using steps similar to those above, calculate the new pH of the solution.

I have a mixture consisting of 0.180 M nitrous acid, and 0.150 M sodium nitrite. NOTE: pKa (nitrous acid) = 3.14. 7.

First, I add 2.00 mL of 0.500 M HCl to 20.00 mL of the original (sodium nitrite / nitrous acid) mixture. Assuming these volumes are additive, make an ICE table and:

a) Write the corresponding balanced reaction, specifying ALL of its relevant reactant and product components.

b) Calculate how many moles of each relevant reaction component are initially present.

c) Calculate the change in the moles of each relevant reaction component.

d) Calculate the moles of each relevant reaction component at equilibrium.

e) Calculate the new molar concentration of nitrite anions.

f) Calculate the new molar concentration of nitrous acid.

g) Calculate the new pH of the resulting mixture.

Fresh orange juice is largely water and solids though much of the flavor comes from volatile organics present in small amounts. In producing concentrated orange juice the trick is to drive off the water but not to loose the organics that produce the taste. If fresh orange juice can be thought of as containing 12.0% solids with the balance being water (ignoring the small amount of organics), concentrated orange juice contains 42.0% solids. Initially a single evaporation process was used for the concentration, but the volatile constituents of the juice escaped with the water, leaving the concentrate with a flat taste. The current process overcomes this to a degree by bypassing the evaporator with a fraction of the fresh juice. The juice that enters the evaporator is concentrated to 58% solids, and the evaporator product stream is mixed with the bypassed fresh juice to achieve the desired final concentration. Calculate the amount of of product (42% concentrate) made and the fraction of the feed that bypasses the concentrator. Why not increase the bypass even more to get greater flavor in the concentrate?

a. Nickel (II) Chloride dissolves in water to form a light green solution. What ions are present in solution? - that is, what is 'swimming around' in the aqueous solution? Write the formulas.

b. Sodium Carbonate dissolves in water to form a colorless solution. What ions are in solution? Write the formulas.

c. When solutions of nickel (II) chloride and sodium carbonate are combined, a green nickel (II) carbonate precipitate forms. What is the formula of the precipitate?

d. Write the ionic equation representing (1) the reactants as they exist in solution before the reaction and (2) the products as they exist in solution after the reaction.

e. What spectator ions remain in solution in the reaction mixture?

f. Write the net ionic reaction that accounts for the appearance for the precipitate.

If anyone could help me, I'd really appreciate it!

The element titanium occurs on earth as titanium (IV) oxide and is found mostly in the mineral called rutile. Rutile is abundant in beach sands in Australia and South Africa. For titanium to be useful, rutile has to be processed to obtain the basic metal form of titanium. Although the process is costly, titanium is gaining popularity as a material for various equipment due to its strength and light weight. One such application is in sports equipment.

1) Explain the chemical process of manufacturing the metal form of titanium.

2) Explain why titanium is a good choice of material for golf clubs. When not in use, discuss at least one precaution to observe when storing clubs?

3) During the fabrication of golf clubs, finely divided titanium is generated, which poses a dangerous risk of fire and explosion. Explain the chemical process involved.

1. hown many grams of Mg must react with HCl in order to produce 80.0 mL of hydrogen gas at STP?
2. when dertermining the pressure of dry hydrogen gas, explain how the measured atmospheric pressure is corrected for the following:
a- the presence of water vapor
b- at level of liquid in the tube higher than in the beacher.
3. what special precautions should be taken when genetating hydrogen gas
4. if 0.071g of magnesium is used in this experiment,what volume of dry H2 gas would theorically be produced if it is measured at 20 celcuis and 785mmHg.
5. what two safery precautions should you take when using concentrated HCl?

17. 1.42 g of a compound containing carbon, hydrogen and oxygen (CXHYOZ) is subjected to combustion analysis. The results show that 1.95 g of CO2 and 1.68 g of H2O were produced. What is the empirical formula for the compound? If the molecular weight of the compound is 160 g/mol, what is the molecular formula of the compound?

2.516 g of a compound containing carbon, hydrogen and oxygen (C_XH_YO_Z) is subjected to combustion analysis.

The results show that 3.082 g of CO₂ and 2.705 g of H₂O were produced.

What is the empirical formula for the compound?

If the molecular weight of the compound is 160.2 g/mol, what is the molecular formula of the compound?   

19.What quantity of NaOH(s) must be added to 1.00 L of 0.200 M HCl to achieve a pH of 12.00? (Assume no volume change.)

20.A 65.5-mL sample of 0.14 M HNO2 (Ka = 4.0 x 10–4) is titrated with 0.11 M NaOH. What is the pH after 26.8 mL of NaOH has been added?

21.

What volume of 0.0100 M NaOH must be added to 1.00 L of 0.0500 M HOCl to achieve a pH of 8.00?

Ka for HOCl is 3.5 x 10–8.