# How Do You Calculate Equilibrium Concentrations in a Redox Reaction?

• cliffordlim
In summary: I also think that the solutions is incomplete; after all, you are supposed to calculate the equilibrium concentrations of the iron and chromium species, and the only one they give is Cr3+. I think they should give you another solution step to find the Fe3+. So maybe you are right that there is something wrong with the problem statement.
cliffordlim

## Homework Statement

Fe2+and Cr2O72- react as follows: 6Fe2+ + Cr2O7 2− + 14H + >>> 6Fe3+ + 2Cr3+ + 7H2O.

The equilibrium constant for the reaction is 1×10^57. Calculate the equilibrium concentrations

of the iron and chromium species if 10 mL each of 0.02M K2Cr2O7 in 1.14M HCl and 0.12M FeSO4

in 1.14M HCl are reacted.

## The Attempt at a Solution

https://physicsforums-bernhardtmediall.netdna-ssl.com/data/attachments/97/97696-2f7ec586395970f64d734682baf6f166.jpg

This is the solution provided . I still don't understand as Cr3+ is 0.02M in the equation as the question give is K2Cr2O7 is 0.02M > does it mean 0.02M of Cr2O72- ? Same goes to iron .

#### Attachments

• Capture.JPG
40.1 KB · Views: 1,292
Last edited by a moderator:
cliffordlim said:
I still don't understand as Cr3+ is 0.02M in the equation as the question give is K2Cr2O7 is 0.02M > does it mean 0.02M of Cr2O72-

Elaborate please, I have no idea what you mean.

Chances are you are forgetting about dilution, but that's just a wild guess.

I think there is a mistake in the text; when it says "At equilibrium 0.02 mol/L Cr2O72- has reacted..." that should be 0.01 mol/L Cr2O72-. Is that the problem? I think the expression here is unclear. But then you say "same goes to iron". Are you just forgetting about dilution, as Borek suggests?

## What is the chemical equilibrium constant?

The chemical equilibrium constant (Kc) is a numerical value that represents the ratio of products to reactants at equilibrium in a chemical reaction. It is a measure of how far a reaction has proceeded towards equilibrium.

## How is the chemical equilibrium constant calculated?

The chemical equilibrium constant is calculated by dividing the concentration of products by the concentration of reactants, with each concentration raised to the power of its coefficient in the balanced chemical equation.

## What factors can affect the value of the chemical equilibrium constant?

The value of the chemical equilibrium constant can be affected by changes in temperature, pressure, and the initial concentrations of reactants and products. Catalysts can also affect the value of Kc, but they do not change the equilibrium position of the reaction.

## What is the significance of a large or small equilibrium constant?

A large equilibrium constant (Kc > 1) indicates that the reaction strongly favors the products at equilibrium, while a small equilibrium constant (Kc < 1) indicates that the reaction strongly favors the reactants at equilibrium. A value of Kc close to 1 indicates that the reaction is close to equilibrium.

## How can the chemical equilibrium constant be used to predict the direction of a reaction?

If the value of Kc is greater than 1, the reaction will favor the products at equilibrium and proceed in the forward direction. If the value of Kc is less than 1, the reaction will favor the reactants at equilibrium and proceed in the reverse direction. If the value of Kc is close to 1, the reaction will not have a strong preference for either direction and may proceed in either direction depending on the initial concentrations of reactants and products.

• Biology and Chemistry Homework Help
Replies
2
Views
3K
• Biology and Chemistry Homework Help
Replies
2
Views
4K
• Biology and Chemistry Homework Help
Replies
2
Views
2K
• Biology and Chemistry Homework Help
Replies
4
Views
2K
• Biology and Chemistry Homework Help
Replies
1
Views
2K
• Chemistry
Replies
5
Views
9K