Water

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Nina Fukui 2J
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Water

Postby Nina Fukui 2J » Fri Jan 08, 2021 7:21 am

Hey guys, I was just wondering when do we include H2O in the ice table???

Lea Chamoun 2J
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Re: Water

Postby Lea Chamoun 2J » Fri Jan 08, 2021 7:44 am

H2O is included in the ICE table when it is in the gas phase. If it is a solve (in the liquid phase), its concentration change is going to be insignificant and it won't be included in the equilibrium constant K, so it does not need to be in the ICE table.

Samudrala_Vaishnavi 3A
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Re: Water

Postby Samudrala_Vaishnavi 3A » Fri Jan 08, 2021 9:00 am

Well, it depends on what state H2O (when it is in liquid form it cancels out) is in. However, I would like to add is that H2O can also be used as a solvent and is placed on both sides of the equation in liquid form so when you write the K constant the concentrations cancel out. When H2O is in gas form, you still need to count its concentration.

Emily Ding 1J
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Re: Water

Postby Emily Ding 1J » Fri Jan 08, 2021 9:01 am

If it is solid or liquid/solvent, don't include it!

Lucy_Balish_3G
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Re: Water

Postby Lucy_Balish_3G » Fri Jan 08, 2021 9:26 am

Only include aqueous and gaseous substances in an ICE table, never a liquid or a solid. So just make sure you double check which phase it is in.

Arnav Saud 2C
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Re: Water

Postby Arnav Saud 2C » Fri Jan 08, 2021 1:45 pm

Only include water when its gaseous. If it's liquid or solid, it shouldn't be included.

Malakai Espinosa 3E
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Re: Water

Postby Malakai Espinosa 3E » Fri Jan 08, 2021 1:52 pm

If H2O is in the liquid or solid phase, then we don't include it in the ICE table. However, if H2O is in the gaseous phase, then we do include it in the table.

Ephrem Gerald 2A
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Re: Water

Postby Ephrem Gerald 2A » Fri Jan 08, 2021 3:43 pm

We would not include water when it is in the solid (ice) or liquid phase because a solid does not change in concentration, and when water is acting as a solvent in the liquid phase its concentration change is so insignificant that it is negligible and we do not include it in the ICE table. It should only be included if it is in the gaseous phase because in that case, its partial pressure can change.

Yashvi Reddy 1H
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Re: Water

Postby Yashvi Reddy 1H » Fri Jan 08, 2021 3:48 pm

Hi! This is a great question that is similar to a topic that came up in my discussion section.

When H20 is a liquid/solid, we do not include it. When it fits the guidelines of being in the gaseous phase, we would then include it. This is because, as a solid, it can't have a concentration, and as a liquid/solvent, its change is not significant enough to acknowledge.

I hope this helps! Have a wonderful rest of your Week 1!

OmarArafat_2K
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Re: Water

Postby OmarArafat_2K » Fri Jan 08, 2021 8:00 pm

Only include H2O in the ice table if it is aqueous and gaseous, never a liquid or a solid. Ensure that you know which phase it is in always.

Xavier Herrera 3H
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Re: Water

Postby Xavier Herrera 3H » Sun Jan 10, 2021 11:22 am

Water is only included when it is a gas that's involved in the reaction. When it's a pure solid or liquid, its concentration doesn't change, so you wouldn't have to include it in the equilibrium constant equation. When water acts as a solvent, there is so much of it compared to the species involved in the reaction that the amount of it on both sides of the reaction are basically the same, so they would cancel out in the K equation.

Ven Chavez 2K
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Re: Water

Postby Ven Chavez 2K » Sun Jan 10, 2021 11:32 am

When water is a solvent and is in a liquid form then it would not be included in the equilibrium equation. If it is in a gas phase, however, then it would be included.

Gabe_Ek 1G
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Re: Water

Postby Gabe_Ek 1G » Sun Jan 10, 2021 11:33 am

OmarArafat_2K wrote:Only include H2O in the ice table if it is aqueous and gaseous, never a liquid or a solid. Ensure that you know which phase it is in always.


Is aqueous not the same as a liquid or am I getting this wrong?

jasonfarrales3D
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Re: Water

Postby jasonfarrales3D » Sun Jan 10, 2021 4:05 pm

We only include water in the ICE box when it is in the gas phase. As mentioned before, if water is a liquid (or even a solid), it is not added as its concentration never changes.

Jaden Joodi 3J
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Re: Water

Postby Jaden Joodi 3J » Sun Jan 10, 2021 4:09 pm

Does anybody mind posting an example of a reaction involving water, in which H2O would be included in the ICE table?

Brian_Wu_3B
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Re: Water

Postby Brian_Wu_3B » Sun Jan 10, 2021 4:59 pm

H20 is only included when it is not a solvent and changes significantly when the reaction occurs.

Tatyana Bonnet 2H
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Re: Water

Postby Tatyana Bonnet 2H » Sun Jan 10, 2021 5:04 pm

Water is only included when it is a gas/ not a solvent. If it is a solid then it does not go in the ICE chart, and if it is a liquid it does not also because it would be acting as a solvent, and the change in concentration of the water in the reaction would be too small to be significant in the value of K.

Lizbeth Garcia 1F
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Re: Water

Postby Lizbeth Garcia 1F » Sun Jan 10, 2021 5:08 pm

Gabe_Ek 1G wrote:
OmarArafat_2K wrote:Only include H2O in the ice table if it is aqueous and gaseous, never a liquid or a solid. Ensure that you know which phase it is in always.


Is aqueous not the same as a liquid or am I getting this wrong?

I believe aqueous means that the material was placed within water which acts as a solvent.

Madeline Louie 1B
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Re: Water

Postby Madeline Louie 1B » Sun Jan 10, 2021 5:35 pm

If water is in a gas phase, is it still included when calculating the equilibrium constant?

Taha 2D
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Re: Water

Postby Taha 2D » Sun Jan 10, 2021 5:37 pm

it is included if its in the gaseous state

Shannon Moore 2L
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Re: Water

Postby Shannon Moore 2L » Sun Jan 10, 2021 7:42 pm

Include it when it is in a gaseous state! Otherwise (when its a solid or liquid) don't include it :)

Uyen Trinh 3C
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Re: Water

Postby Uyen Trinh 3C » Sun Jan 10, 2021 8:01 pm

I agree with everyone else. But just wanted to add the reason why we do not include water in a liquid state. As aforementioned by Professor Lavelle, anything in a solid or liquid state should not be included in the K expression. When water is in a liquid state, it is omitted because the change in its concentration is insignificant. In the reaction, water is acting as a solvent and since the concentration of reactants is so much less than the solvent's, the change in concentration is negligible. Thus, in the K expression, the concentration of water in the numerator and denominator would cancel out. Also, sometimes water might not even be included in the equation as it is the implied solvent.

joshtully
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Re: Water

Postby joshtully » Sun Jan 10, 2021 8:02 pm

Only include water when it is a gas, not solid or liquid.

Angel More
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Re: Water

Postby Angel More » Sun Jan 10, 2021 8:03 pm

In general, don't include anything that is a solid or liquid or solvent in your calculations.

Linette Choi 3L
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Re: Water

Postby Linette Choi 3L » Sun Jan 10, 2021 8:45 pm

Gabe_Ek 1G wrote:
OmarArafat_2K wrote:Only include H2O in the ice table if it is aqueous and gaseous, never a liquid or a solid. Ensure that you know which phase it is in always.


Is aqueous not the same as a liquid or am I getting this wrong?

Aqueous is slightly different than liquid as liquid is a pure form while aqueous is when something is dissolved in a solvent.

Keon Amirazodi 3H
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Re: Water

Postby Keon Amirazodi 3H » Sun Jan 10, 2021 8:46 pm

Only aqueous solutions and gasses are included in ice tables.

Aydin Karatas 1F
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Re: Water

Postby Aydin Karatas 1F » Sun Jan 10, 2021 8:51 pm

Any solvents, liquids, and solids are not included in concentration calculations. So, unless the water is in gas form, its concentration is not used because it either doesn't have a concentration (such as when it is a liquid or solid precipitate) or has a negligible concentration (such as when it is a solvent).

Queena Chu 3E
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Re: Water

Postby Queena Chu 3E » Sun Jan 10, 2021 9:00 pm

If H2O is in the gaseous phase, then we would include it in the ICE table but not when in the liquid or solid phase.

nayha a 1E
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Re: Water

Postby nayha a 1E » Sun Jan 10, 2021 9:01 pm

Hi there! I believe we only include it when it is gaseous! Hope this helps (:


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