## 5G1 true/false

705121606
Posts: 68
Joined: Wed Sep 18, 2019 12:17 am

### 5G1 true/false

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

### Re: 5G1 true/false

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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Joined: Sat Aug 17, 2019 12:17 am
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### Re: 5G1 true/false

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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Joined: Sat Aug 17, 2019 12:17 am
Been upvoted: 2 times

### Re: 5G1 true/false

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
Posts: 106
Joined: Wed Feb 20, 2019 12:16 am

### Re: 5G1 true/false

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
Posts: 125
Joined: Wed Oct 02, 2019 12:16 am

### Re: 5G1 true/false

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
Posts: 100
Joined: Wed Sep 18, 2019 12:20 am

### Re: 5G1 true/false

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

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

Tyler Angtuaco 1G
Posts: 130
Joined: Wed Sep 11, 2019 12:16 am

### Re: 5G1 true/false

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."