Chemistry - May 2007

2 H2S(g) + SO2(g) <===> 3 S(s) + 2 H2O(g)
At 298 K, the standard enthalpy change, Ho, for the reaction represented above is -145 kilojoules.
a. Predict the sign of the standard entropy change, So, for the reaction. Explain the basis for
your prediction.
b. At 298 K, the forward reaction (i.e., toward the right) is spontaneous. What change, if any, would occur in the value of Go for this reaction as the temperature is increased? Explain your reasoning using thermodynamic principles.
c. What change, if any, would occur in the value of the equilibrium constant, Keq, for the situation
described in (b)? Explain your reasoning.
d. The absolute temperature at which the forward reaction becomes nonspontaneous can be predicted. Write the equation that is used to make the prediction. Why does this equation predict only an approximate value for the temperature?

2007-05-06 15:14:12 · 1 answers · asked by fkdfolf 1

A direct current of 0.125 ampere was passed through 200 milliliters of a 0.25 molar solution of Fe2(SO4)3 between platinum electrodes for a period of 1.100 hours. Oxygen gas was produced at the anode. The only change at the cathode was a slight change in the color of the solution.

At the end of the electrolysis, the electrolyte was acidified with sulfuric acid and was titrated with an aqueous solution of potassium permanganate. The volume of the KMnO4 solution required to reach the end point was 24.65 milliliters.
a. How many faradays were passed through the solution?
b. Write a balanced half-reaction for the process that occurred at the cathode during the electrolysis.
c. Write a balanced net ionic equation for the reaction that occurred during the titration with potassium permanganate.
d. Calculate the molarity of the KMnO4 solution.

2007-05-06 15:13:13 · 1 answers · asked by fkdfolf 1

A direct current of 0.125 ampere was passed through 200 milliliters of a 0.25 molar solution of Fe2(SO4)3 between platinum electrodes for a period of 1.100 hours. Oxygen gas was produced at the anode. The only change at the cathode was a slight change in the color of the solution.

At the end of the electrolysis, the electrolyte was acidified with sulfuric acid and was titrated with an aqueous solution of potassium permanganate. The volume of the KMnO4 solution required to reach the end point was 24.65 milliliters.
a. How many faradays were passed through the solution?
b. Write a balanced half-reaction for the process that occurred at the cathode during the electrolysis.
c. Write a balanced net ionic equation for the reaction that occurred during the titration with potassium permanganate.
d. Calculate the molarity of the KMnO4 solution.

2007-05-06 15:10:28 · 1 answers · asked by fkdfolf 1

2007-05-06 15:09:57 · 1 answers · asked by ca 2

enthalpy is the trangle H symbol

2007-05-06 15:06:00 · 1 answers · asked by ca 2

1 curie of radiation is equal to 3.7 x 10^10 decay events per second (the number of decay events from 1 g of radium in 1 s)

What mass of Na(2)38-SO4 has an activity of 10.0 mCi? Sulfur-38 has an atomic mass of 38.0 and a half-life of 2.87 h.

I am completey confused on this one, I cant find an example in my textbook either,Any ideas or an equations i should use

2007-05-06 14:38:14 · 1 answers · asked by bid 1

2007-05-06 13:26:06 · 5 answers · asked by mgibsona1 1

2007-05-06 11:18:37 · 5 answers · asked by Anonymous

CRYSTAL PEPSI-Pepsi's equivalent of Coke's NEW COKE, Crystal Pepsi was manufactured from 1992-1993, well there is a can of one unopened Diet Crystal Pepsi on eBay for twenty dollars, so what if I bought it...and drank it, how would it taste?

2007-05-06 11:10:19 · 1 answers · asked by Anonymous

I need help with this chemistry question!!!

2007-05-06 11:08:37 · 3 answers · asked by RTechAide55 1

or do u no any site that can help me?

2007-05-06 10:28:14 · 2 answers · asked by liloofar 3

I am looking for help in finding the ionic and net ionic equations for ammonium phosphate, (NH4)3PO4 and aluminum sulfate, Al2(SO4)3

2007-05-06 10:24:36 · 1 answers · asked by flowers4eden 1

Can anyone tell me what the net ionic equation is for Sodium bromide, NaBr, and silver nitrate, AgNO3?

2007-05-06 10:21:41 · 1 answers · asked by flowers4eden 1

2007-05-06 09:52:05 · 2 answers · asked by tim_childress 1

If I substitute water with ammonium hydroxide will the crystals grow if they dont why not?

Please source

2007-05-06 09:36:40 · 1 answers · asked by burninhotboi 2

A) color
B) volume
C) identity
D) mass

2007-05-06 09:28:08 · 2 answers · asked by Anonymous

2007-05-06 08:56:55 · 1 answers · asked by jacque c 1

Can you account for the difference in pH of the oxides of period 3? i know it starts of as basic then going to acidic.. but why?

2007-05-06 08:52:14 · 1 answers · asked by RT 2

what particle is emitted durring the nuclear decay of a Po-218 atom?



#2) If a scientist purifies 1.0 gram of radium-226, how many years must pass before only 0.50 gram of the original radium-226 radium sample remains?

#3)decay of c-14 equation? atomic # and mass too
14/6C ---> _____ + 0/-1e

2007-05-06 08:38:46 · 2 answers · asked by SaxiPHNgurl3 2

An increase in the partial pressure of BrF3 in this reaction at equilibrium would be favored by a (higher, lower) total pressure and by a (higher, lower) temperature.
1. higher; higher
2. higher; lower
3. lower; higher
4.lower; higher

2007-05-06 08:30:25 · 1 answers · asked by Anonymous

2007-05-06 08:29:48 · 4 answers · asked by jacque c 1

why does the U-238 disintegration series end w/ nuclide Pb-206?


2)nuclear decay of the radioisotope used to study red blood cells equation?
59/26 Fe --> ______+______
24 na halflife = 15hrs
59 Fe halflife - 44.5 days
131I halflife = 8.1 days
all are betas

2007-05-06 08:25:21 · 1 answers · asked by SaxiPHNgurl3 2

2007-05-06 08:24:05 · 3 answers · asked by Anonymous

2007-05-06 08:07:46 · 5 answers · asked by uma c 1

Calcium fluoride, CaF2, is a nearly insoluble salt with a Ksp= 3.9 x 10^-11 at 298K. Addition of which substance is most likely to increase the solubility of CaF2 at constant temperature??
a- NaF (Solid)
b- CaCl2 (solid)
c- HCl (aqueous)
d- H20
e- C2H5OH (liquid)

and why??

thanks!

2007-05-06 08:07:41 · 2 answers · asked by Anonymous

ok...this ones kinda tricky...i have four different choices, but one needs to be changed so that it is correct....

Which solution, when appropriately combined, could be used to produce a buffer??
a- HCl and NaOH
b- HNO2 and NaNO3
c- KI and KOH
d- HF and NaOH

thanks!

2007-05-06 08:03:00 · 2 answers · asked by Anonymous

whats the notation for the alpha particles emitted by radium in radium salts?

also,...

The radioisotopes carbon-14 & nitrogen-16 are present in a living organism, carbon-14 is commonly sed to date a once-living organism.
A wood sample is found to contain 1/8 as much c-14 as of present wood of a tree. what is the approximate age (in years) of the wood?

2007-05-06 07:58:15 · 1 answers · asked by SaxiPHNgurl3 2

do coefficiants and or subscripts change the electronegativity number of a compound? thanks!

2007-05-06 07:51:14 · 1 answers · asked by Anonymous

Thanks for your help

2007-05-06 07:39:08 · 4 answers · asked by Anonymous

Then we decrease the total pressure by increasing the volume of the container. What will be the effect on the amount of SO3(g) present?
1. It doesn't change.
2. The question cannot be answered without some knowledge of the value of /\H.
3. The question cannot be answered without some knowledge of the value of Kc or Kp.
4. It increases.
5. It decreases.

2007-05-06 07:37:25 · 4 answers · asked by Anonymous