Sapling Week 1 #5

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Jaclyn Schwartz 1I
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Joined: Wed Sep 30, 2020 9:45 pm

Sapling Week 1 #5

Postby Jaclyn Schwartz 1I » Sun Jan 17, 2021 9:33 pm

For question 5, I understand how to cancel all the equations and convert the k values. But how do we combine the k values for the total K? I used equations Ka and Kc and was able to convert them but how to you combine the two new k values? And tips would be appreciated!

Varsha Ravi 3E
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Re: Sapling Week 1 #5

Postby Varsha Ravi 3E » Sun Jan 17, 2021 9:35 pm

Once you've created two equations that can be combined into the final equation, you take the equilibrium constants of the individual reactions and multiply them against each other (K(combined) = K1 x K2)

Natalie 3k
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Re: Sapling Week 1 #5

Postby Natalie 3k » Sun Jan 17, 2021 9:39 pm

It's important to remember that if a reaction is reversed, the k value will be the inverse of the value shown, and if it is multiplied by a certain value (like 3 of one equation) then that k value is raised to that power. Once you get those values you multiply them together and that should give you the answer!

Aliya 1H
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Re: Sapling Week 1 #5

Postby Aliya 1H » Sun Jan 17, 2021 9:40 pm

^^ as she said, multiply them. If you're on sapling also watch out for sig figs because I had to take a few attempts just from little calculator/sig fig errors

kristinalaudis3e
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Re: Sapling Week 1 #5

Postby kristinalaudis3e » Sun Jan 17, 2021 11:34 pm

yes just multiply them!!

Amanda Bueno-Kling
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Re: Sapling Week 1 #5

Postby Amanda Bueno-Kling » Sun Jan 17, 2021 11:41 pm

You multiply them, but make sure to inverse for a reaction going in reverse! Also make sure to put any exponents you need to scale the given values up. For my problem, I multiplied 27.7778 (the inverse of 3.6×10^−2) with 160^3 (the third power was to scale the 2HI in the given equations with the 6HI I was looking for). This gave me the right answer.
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Uyen Trinh 3C
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Joined: Thu Nov 14, 2019 12:17 am

Re: Sapling Week 1 #5

Postby Uyen Trinh 3C » Sun Jan 17, 2021 11:45 pm

I find it really helpful to go online and find examples of similar problems to look at and follow. If I'm feeling snazzy that day I'll go on Youtube to watch video examples, if not I just type in "__topic__ worked examples" and many resources will come up.

For this particular Sapling question, you can look at sample exercise 15.5 in the pdf below:

https://www.centrallyon.org/pages/uploaded_files/Chapter%2015%20Worked%20Examples.pdf

Good luck!

David Liu 1E
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Joined: Wed Sep 30, 2020 10:07 pm

Re: Sapling Week 1 #5

Postby David Liu 1E » Mon Jan 18, 2021 12:56 am

you multiply them to add them together!

Siwa Hwang 3G
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Joined: Wed Sep 30, 2020 9:48 pm

Re: Sapling Week 1 #5

Postby Siwa Hwang 3G » Mon Jan 18, 2021 12:58 am

You should multiply the k’s to get the final reaction constant


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