Equilibrium Position: How Water Affects System

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Discussion Overview

The discussion revolves around the effects of adding water to a chemical system at equilibrium, specifically focusing on how this addition influences the equilibrium position and the concentrations of reactants and products. The scope includes theoretical reasoning and chemical equilibrium concepts.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • One participant asks how the equilibrium position changes with the addition of water.
  • Another participant presents a chemical equation involving Co^2+ and Cl^- ions, suggesting a context for the discussion.
  • Some participants argue that the concentration of reactants will decrease due to increased volume, leading to a lower Q value compared to K, thus favoring the forward reaction.
  • There is a question raised about whether a lower concentration results in a smaller Q value compared to K.
  • A later reply suggests that the dilution may lead to a greater degree of dissociation of the complex, contradicting earlier claims about the forward reaction being favored.
  • Another participant proposes that the rate of the forward reaction decreases quadratically with dilution, while the backward reaction decreases linearly, suggesting a shift towards the reactants.
  • One participant suggests recalculating Q based on new concentrations after dilution and comparing it to Keq to reason out the effects.
  • According to Ostwald's law, one participant notes that the degree of dissociation increases with dilution, adding another layer to the discussion.

Areas of Agreement / Disagreement

Participants express differing views on how dilution affects the equilibrium position, with some arguing for a shift towards products and others suggesting a shift towards reactants. The discussion remains unresolved with multiple competing perspectives.

Contextual Notes

Limitations include assumptions about the behavior of the system under dilution, the dependence on specific definitions of concentration and equilibrium, and unresolved mathematical steps in the reasoning provided.

nicolauslamsiu
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I want to ask how will the equilibrium position of the system change if water is added to the system?
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Co^2+(aq.) + 4cl^-1(aq.) =cocl4^2-(aq.)
 
The concentration will decrease because the volume will increase. This will make Q lower than the K value so the forward reaction should be favored(shifts right)
 
Will the value of Q become smaller the K if the concentration is lower?
 
*become greater
 
Can you rephrase your question, I'm not sure I understand.
 
AlphaEmission said:
The concentration will decrease because the volume will increase. This will make Q lower than the K value so the forward reaction should be favored(shifts right)

Quite the opposite, the more diluted the solution, the more dissociated the complex is.
 
By adding water the rate of the forward reaction decreases X to the power 2 times while the rate of the backward reaction will decrease only X times so the reaction moves backwards
 
Pretend the Keq is 1, and all species' molarity is 1 at the equilibrium. Now do the dilution recalculate Q based on the new concentrations. Compare Q with Keq and reason it out.
 
  • #10
And according to Ostwald's law : degree of dissociation increases by increasing dilution
 

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