# Homework Help: Derive equillibrium constant

1. Aug 15, 2008

### vinayakp

How to derive equillibrium constant (K) of reaction with respect to water eq. constant (KH2O) ?

Reactions

H+ + HCO3- ----------> H2CO3

H+ + CO3-2 -----------> HCO3-

Fe2+ + Cl- ----------> FeCl+

Fe2+ + CH3COO- ----------> Fe( CH3COO)+

2. Aug 20, 2008

### Astronuc

Staff Emeritus
Please attempt to write the equations oneself. Is there not an example in one's Chemistry textbook?

3. Aug 20, 2008

### symbolipoint

Here is just a wild guess about the dissociation constant for water; I do not know if it is actually how the constant was found:

Conductivity Measurements!

Pure, extra pure water could have been used, assuming dissociation would occur something like, in the simplest manner H2O <===> H+ + OH-
The resulting ions in solution will conduct electricity, therefore measurement of conductivity may correlate with concentration of the ions.

The concentration of the H2O is assumed not to change and does not occur in the mathematical expression. K = [H]*[OH]