## ICE tables

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Noe BM 1J
Posts: 50
Joined: Sat Sep 07, 2019 12:17 am

### ICE tables

How do you know whether to use the concentration or pressure of a gas when doing ICE tables? Also, if I use the pressure of a gas, what units do I use?

Paul Hage 2G
Posts: 105
Joined: Thu Jul 25, 2019 12:17 am

### Re: ICE tables

Usually, concentration would be used in ICE tables, but the only way to know what to use is by checking whether the Kp or Kc is given in the problem or whether the problem gives you initial concentrations or initial partial pressures. If you use the pressure of a gas, it would typically be in units of atm.

805422680
Posts: 103
Joined: Sat Sep 14, 2019 12:16 am

### Re: ICE tables

The ICE box is used for concentrations to calculate the concentration of reactants and products at equilibrium given a Kc value. If there is a Kp value given, then pressure in the units atm will be used.

Luc Zelissen 1K
Posts: 57
Joined: Mon Jun 17, 2019 7:23 am

### Re: ICE tables

If the questions asks for just K, and not Kc or Kp, then you need to look at the equation. If the reactants and products are gases then you should use Kp, because it is implied. If the reactants and products of the equation are aqueous then you should use Kc because it is implied. However if it asked for either Kc or Kp you should write you answer with either or, but remember to make sure you label what kind of K value that you are using.

Maya Pakulski 1D
Posts: 105
Joined: Thu Jul 11, 2019 12:17 am

### Re: ICE tables

Luc Zelissen 1K wrote:If the questions asks for just K, and not Kc or Kp, then you need to look at the equation. If the reactants and products are gases then you should use Kp, because it is implied. If the reactants and products of the equation are aqueous then you should use Kc because it is implied. However if it asked for either Kc or Kp you should write you answer with either or, but remember to make sure you label what kind of K value that you are using.

So can you use pressure in an ICE table? Or you can only use concentrations?

AngieGarcia_4F
Posts: 120
Joined: Thu Jul 25, 2019 12:17 am

### Re: ICE tables

I think it would depend on the information given in the question (concentration or pressure). The units for pressure are usually atm or bar.

Andrew Liang 1I
Posts: 105
Joined: Fri Aug 30, 2019 12:18 am

### Re: ICE tables

It does not matter which unit is given, ICE table works as long as we keep the unit the same through out the calculation. Bar or atm are usually used for pressure of a gas.

Kassidy Ford 1I
Posts: 103
Joined: Sat Aug 17, 2019 12:16 am
Been upvoted: 1 time

### Re: ICE tables

Maya Pakulski 1D wrote:
Luc Zelissen 1K wrote:If the questions asks for just K, and not Kc or Kp, then you need to look at the equation. If the reactants and products are gases then you should use Kp, because it is implied. If the reactants and products of the equation are aqueous then you should use Kc because it is implied. However if it asked for either Kc or Kp you should write you answer with either or, but remember to make sure you label what kind of K value that you are using.

So can you use pressure in an ICE table? Or you can only use concentrations?

Yes you can use pressure in an ice table!

Maya Beal Dis 1D
Posts: 100
Joined: Sat Aug 17, 2019 12:16 am
Been upvoted: 2 times

### Re: ICE tables

In lecture on Wednesday Lavelle showed us how to approximate when using ICE tables so you do not have to use the quadratic equation. Are we allowed to use this approximation on a test assuming it is less then 5% the initial value or would we need to use the quadratic equation to receive full credit?

205405339
Posts: 77
Joined: Thu Jul 11, 2019 12:16 am

### Re: ICE tables

usually questions will include words like "moles" which is used for concentrations. if it doesnt have "moles" i would guess pressures is the way to go