determining shift in equilibrium

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Katherine Wu 1H
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determining shift in equilibrium

Postby Katherine Wu 1H » Thu Jan 09, 2020 3:47 pm

Determine the shift in equilibrium position, if any, which will occur when the temperature is increased.
The hydrolysis of ATP: ATP(aq) + H2O (l) ⇌ ADP + PO4^-2(aq) delta H°= -30 kJ/mol

The answer says that it shifts to the left. Do I just take into account the delta to determine the shift? Also, in this case, the temperature increasing doesn't have any effect right?

Chem_Mod
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Re: determining shift in equilibrium

Postby Chem_Mod » Thu Jan 09, 2020 3:54 pm

Yes, the delta H indicates whether heat is released or absorbed. Since it's negative, heat is released and can be seen as a "product." Therefore, increasing heat would push the reaction in the reverse direction.

Goyama_2A
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Re: determining shift in equilibrium

Postby Goyama_2A » Thu Jan 09, 2020 3:56 pm

Because the change in energy is negative, the reaction is exothermic. The answer is that the reaction shifts to the left because the reaction is exothermic and thus decreasing temperature would move the reaction in the forward. Therefore, increasing temperature would do the opposite.

Abhi Vempati 2H
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Re: determining [censored] in equilibrium

Postby Abhi Vempati 2H » Thu Jan 09, 2020 3:56 pm

Yes, you need to take the ΔH into account. Since ΔH < 0, the forward reaction is exothermic and the reverse reaction is endothermic. In other words, the forward reaction gives off heat and the reverse reaction uses up heat.

Since heat is added, Le Chatelier's Principle states that the system will try to minimize this change by absorbing/using up the heat. This is done when the reverse reaction occurs, meaning that more products will be formed. This causes the equilibrium to shift to the left.

Jocelyn Thorp 1A
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Re: determining [censored] in equilibrium

Postby Jocelyn Thorp 1A » Thu Jan 09, 2020 5:25 pm

Abhi Vempati 2H wrote:Yes, you need to take the ΔH into account. Since ΔH < 0, the forward reaction is exothermic and the reverse reaction is endothermic. In other words, the forward reaction gives off heat and the reverse reaction uses up heat.

Since heat is added, Le Chatelier's Principle states that the system will try to minimize this change by absorbing/using up the heat. This is done when the reverse reaction occurs, meaning that more products will be formed. This causes the equilibrium to shift to the left.


this explanation makes a lot of sense, thanks!


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