• Set Yourself Up For Success Webinar

    October 6, 2021 at 2 PM Eastern/11 AM Pacific
    SDN and Osmosis are teaming up to help you get set up for success this school year! We'll be covering study tips, healthy habits, and meeting mentors.

    Register Now!

  • Funniest Story on the Job Contest Starts Now!

    Contest starts now and ends September 27th. Winner will receive a special user banner and $10 Amazon Gift card!

    JOIN NOW
  • Site Updates Coming Next Week

    Site updates are coming next week on Monday, Wednesday, and Friday. Click the button below to learn more!

    LEARN MORE

DAT Destroyer- G-chem #123

toothteethtooth

Full Member
7+ Year Member
Dec 5, 2013
70
76
226
In this problem, they have done an ICE table for the Kp Problem. I understand that Kp is to be calculated the same way as other K constants such as Ksp and etc. However, in the solutions, they did an ICE table to solve for the Kp They have not canceled out the "X" amount from A or B (both reactants) as it was always considered negligible when I did the Ksp Problems. Chad's videos also shows that X is really low compared to the given concentrations so you cross it out and solve for the rest. In Destroyer, the negligible X amount in the calculation is kept in the answer until the end and solved for. This is a little different than doing calculations for the Ksp ICE table. Can anyone explain me the difference on why X was not considered negligible in this?

I hope I make sense, if not I apologize. DAT in 15 days so I am kind of going crazy!!!!
 

Pearl E. White

D3 at LECOM
7+ Year Member
May 20, 2014
1,105
996
216
Bradenton, FL
  1. Dental Student
In this problem, they have done an ICE table for the Kp Problem. I understand that Kp is to be calculated the same way as other K constants such as Ksp and etc. However, in the solutions, they did an ICE table to solve for the Kp They have not canceled out the "X" amount from A or B (both reactants) as it was always considered negligible when I did the Ksp Problems. Chad's videos also shows that X is really low compared to the given concentrations so you cross it out and solve for the rest. In Destroyer, the negligible X amount in the calculation is kept in the answer until the end and solved for. This is a little different than doing calculations for the Ksp ICE table. Can anyone explain me the difference on why X was not considered negligible in this?

I hope I make sense, if not I apologize. DAT in 15 days so I am kind of going crazy!!!!
What version of Destroyer is this? I have 2017 and my 123 is a cell potential question. Let me know and I will try to help.
 
  • Like
Reactions: 1 user

orgoman22

DAT DESTROYER
Account on Hold
Sponsor
Vendor
15+ Year Member
Mar 12, 2005
4,576
3,362
346
New York City
www.orgoman.com
  1. Non-Student
In this problem, they have done an ICE table for the Kp Problem. I understand that Kp is to be calculated the same way as other K constants such as Ksp and etc. However, in the solutions, they did an ICE table to solve for the Kp They have not canceled out the "X" amount from A or B (both reactants) as it was always considered negligible when I did the Ksp Problems. Chad's videos also shows that X is really low compared to the given concentrations so you cross it out and solve for the rest. In Destroyer, the negligible X amount in the calculation is kept in the answer until the end and solved for. This is a little different than doing calculations for the Ksp ICE table. Can anyone explain me the difference on why X was not considered negligible in this?

I hope I make sense, if not I apologize. DAT in 15 days so I am kind of going crazy!!!!

When you are solving an acid base problem that involves a Ka or Kb......even a Ksp problem, we will always neglect the x in the denominator. We do this because we are assuming that only a small amount has dissociated or ionized. Without this assumption, a quadratic would be needed. The DAT exam will have calculations in which the approximation holds nicely. I have written up two questions using the ICE table....where you have INITIAL amounts of reactants in an equilibrium expression. The numbers are easy to work with, and although not likely to appear on the exam, it is good practice.

Hope this helps.

Dr. Romano
 
This thread is more than 4 years old.

Your message may be considered spam for the following reasons:

  1. Your new thread title is very short, and likely is unhelpful.
  2. Your reply is very short and likely does not add anything to the thread.
  3. Your reply is very long and likely does not add anything to the thread.
  4. It is very likely that it does not need any further discussion and thus bumping it serves no purpose.
  5. Your message is mostly quotes or spoilers.
  6. Your reply has occurred very quickly after a previous reply and likely does not add anything to the thread.
  7. This thread is locked.