5G1 true/false


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705121606
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Joined: Wed Sep 18, 2019 12:17 am

5G1 true/false

Postby 705121606 » Thu Jan 09, 2020 10:07 pm

The question asks to determine if the statement is true or false and explain why. In part c it states "If one starts with higher pressure of reactant, the equilibrium constant will be larger." I thought this was true because if there is higher pressure of reactant it will shift toward the products. Since the equilibrium constant is equal to concentration of products over concentration of reactants, the equilibrium constant would be larger. Can someone explain why the statement is false.

205405339
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Re: 5G1 true/false

Postby 205405339 » Thu Jan 09, 2020 10:11 pm

Instead of looking at K as Kc look at it as Kp. Kp= (partial pressure of products) / (partial pressure of reactants)
according to this equation, an increase in the partial pressure of reactants would lead to a decrease in the equilibrium constant instead of an increase in the equilibrium constant, which is what the question is asking. Therefore, it would be false since K would be decreasing instead of increasing

Wendy 1E
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Re: 5G1 true/false

Postby Wendy 1E » Thu Jan 09, 2020 10:27 pm

Your reasoning that "if there is higher pressure of reactant, it will shift towards product" is correct. However, this does not mean that K will change. Here, only Q is changing because initially Q<K. K is not changing. This is because the temperature is constant. Only when the temperature changes (we will probably learn this in future lectures), will K then change. The pressure of the reactants and products don't affect the equilibrium constant.

Wendy 1E
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Re: 5G1 true/false

Postby Wendy 1E » Thu Jan 09, 2020 10:30 pm

205405339 wrote:Instead of looking at K as Kc look at it as Kp. Kp= (partial pressure of products) / (partial pressure of reactants)
according to this equation, an increase in the partial pressure of reactants would lead to a decrease in the equilibrium constant instead of an increase in the equilibrium constant, which is what the question is asking. Therefore, it would be false since K would be decreasing instead of increasing


This is not correct because when you increase the pressure of the reactants, the pressure of the products will also increase. Therefore, the ratio would still be the same and K will not be affected. K will only change if the temperature changes.

205150314
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Joined: Wed Feb 20, 2019 12:16 am

Re: 5G1 true/false

Postby 205150314 » Thu Jan 09, 2020 10:39 pm

705121606 wrote:The question asks to determine if the statement is true or false and explain why. In part c it states "If one starts with higher pressure of reactant, the equilibrium constant will be larger." I thought this was true because if there is higher pressure of reactant it will shift toward the products. Since the equilibrium constant is equal to concentration of products over concentration of reactants, the equilibrium constant would be larger. Can someone explain why the statement is false.


It is false because the equilibrium constant is well constant, so even if you start with a higher pressure of reactant the reaction will create more products and in the end lead to the same value of K

Junwei Sun 4I
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Re: 5G1 true/false

Postby Junwei Sun 4I » Thu Jan 09, 2020 11:37 pm

This statement is false since even if you start with a higher pressure of reactants, this would only result in production of more products and in the end the equilibrium constant remains the same.The value of K is not affected by the addition of products and reactants as long as the temperature is the same.

Ruth Glauber 1C
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Re: 5G1 true/false

Postby Ruth Glauber 1C » Fri Jan 10, 2020 9:16 am

It's false because when you increase the pressure of the reactants, the pressure of the products will also increase.

rohun2H
Posts: 100
Joined: Wed Sep 18, 2019 12:19 am

Re: 5G1 true/false

Postby rohun2H » Fri Jan 10, 2020 9:50 am

Q would be larger but ultimately the reaction would reach equilibrium and K remains the same.

Tyler Angtuaco 1G
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Re: 5G1 true/false

Postby Tyler Angtuaco 1G » Fri Jan 10, 2020 10:24 am

A higher initial amount of reactant would produce more product. The equilibrium values of the reactant and product will also be higher and the numerator and denominator of the equilibrium constant ratio will be proportional to those of a reaction with less reactant if both reactions occur under the same conditions and stoichiometric coefficients are calculated. Keep in mind that the initial values and equilibrium values are not necessarily proportional to those produced from a reaction with less reactant. So, when calculating the equilibrium constant, you might have a higher numerator (due to the larger equilibrium amount of product), and a higher denominator (due to the larger equilibrium amount of reactant), but the ratio will simplify to the same number for a reaction with a smaller amount of reactant as long as both reactions occur under the same conditions, i.e. temperature. The terminology of the statement also points to why it would be false, since it seems to assume higher initial pressures always result in a higher equilibrium constant due to their inclusion of the word, "will."


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