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Topic: Test question  (Read 1881 times)

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Offline Zezwaz

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Test question
« on: February 17, 2021, 03:08:36 AM »
I genuinely have no idea where to start with these questions. I think it is asking about chemical equilibrium, But I am not really sure. Let me know if you guys can help me solve it. Or just teach me where to look so I can solve it myself.



The following mechanism is proposed for the reaction between hydrogen and iodine monochloride:
Step 1:                H2+ ICl →HI + HCl
Step 2:                HI + ICl →I2+ HCla.
Write the balanced equation for the overall reaction. All components are gaseous.
b. Identify any intermediate(s) and/or catalyst(s) in the reaction.c. If the first step is slow, what would you expect to be the rate law for the overall reaction?
d. If the second step is slow, and the first step is fast and reversible, what do you expect to be the rate law for the overall reaction?
e. If the following data were obtained, which mechanism is supported? Explain.

2.00 grams of a calcium-containing ionic compound is dissolved in water to make a 0.010 M solution of this compound and it is found to have an osmotic pressure of 0.674atm at 298 K. Using this information, suggest the most likely identity of the compound. Themysteryanion can be either a monoatomic anion or a common polyatomic ion.

b. Would a more concentrated or less concentrated solution make your answer to the previous question more certain? Explain your answer.


Offline mjc123

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Re: Test question
« Reply #1 on: February 17, 2021, 05:53:01 AM »
Please read forum rules. You have to show an attempt before receiving help.

I refuse to believe you have no idea. Have you studied kinetics and osmotic pressure? If not, why are you answering questions on them? If you have, what do you know about them? Do you know a formula for osmotic pressure, for example?

And your questions are incomplete. Q1e - what following data?
Q2 - how much water? (1 L would give a sensible answer.)

Offline Zezwaz

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Re: Test question
« Reply #2 on: February 17, 2021, 03:26:29 PM »
My bad all, I wrote this when very tired last night, I figured most of this out. All I have left is E, I am not sure what it means by what mechanism it supports. Is this a question of what does it validate? Here is the data for E


Offline mjc123

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Re: Test question
« Reply #3 on: February 18, 2021, 05:47:57 AM »
You were asked (which you say you've figured out), under two different assumptions, what you expect the rate law to be. In each case, how do you expect [ICl] to vary with time? Which model are the data most consistent with? You need to integrate the rate equation and plot an appropriate graph for each case.

I am assuming , BTW, that H2 is pseudo-zero-order (i.e. it is in such excess that its concentration virtually doesn't change during the reaction, so the rate only depends on [ICl]).

Offline Orcio_87

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Re: Test question
« Reply #4 on: March 16, 2021, 07:40:25 AM »
Quote
The following mechanism is proposed for the reaction between hydrogen and iodine monochloride:
Step 1:                H2+ ICl →HI + HCl
Step 2:                HI + ICl →I2+ HCla.
Write the balanced equation for the overall reaction. All components are gaseous.
b. Identify any intermediate(s) and/or catalyst(s) in the reaction.c. If the first step is slow, what would you expect to be the rate law for the overall reaction?
d. If the second step is slow, and the first step is fast and reversible, what do you expect to be the rate law for the overall reaction?
e. If the following data were obtained, which mechanism is supported? Explain.

Catalyst will be HI, as it is restored in course of reaction.

Overall reaction:

H2 + 2 ICl  :rarrow: 2 HCl + I2

If first reaction (H2 + ICl) is slow then overall kinetics will be:

v = k [H2] x [ICl]2

If first reaction (H2 + ICl) is fast and reversible then:

v = k [HI] x [ICl] x [H2]

about supported mechanism I will answer you later (when I come back home).
« Last Edit: March 16, 2021, 07:54:22 AM by Orcio_Dojek »

Offline Orcio_87

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Re: Test question
« Reply #5 on: March 16, 2021, 05:51:30 PM »
As of supported mechanism - empirical data fits better for second model (first reaction fast and reversible).


Offline Babcock_Hall

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Re: Test question
« Reply #6 on: March 16, 2021, 06:24:45 PM »
Orcio,

In my judgement the OP has not shown much of his or her own work, a requirement for receiving help on this forum.

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