Chemical Equilibrium Experimental Results

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Chemical Equilibrium Experimental Results

By | Jan. 2013
Page 1 of 8
Chemical Equilibrium



A. Iron-Silver Equilibrium

In studying equilibrium between iron and silver, 0.10 M FeSO4 and 0.10 M AgNO3 were used. The balanced equation for the reaction is:

FeSO4 (aq) + 2 AgNO3 (aq) ↔ Fe(NO3)2 (aq) + Ag2SO4 (s)

It has a net equation of:

Fe2+(aq) + Ag+(aq) ↔ Fe3+(aq) + Ag(s)
This part of the experiment required centrifugation of the solution. This was done to completely separate the precipitate from the supernate for easier decantation process.

In determining the presence of Fe2+ in the supernate, 0.10 M of K3Fe(CN)6 was used . The resulting product had a Prussian blue precipitate. The reaction has a balanced equation of:

3 Fe(NO3)2 (aq) + K3Fe(CN)6 (aq) ↔ 3 Fe(CN)2 + K3Fe(NO3)6

It has a net ionic equation of:

Fe2+(aq) + K3Fe(CN)6(aq) ↔ KFe(III)Fe(II)(CN)6(s) + 2K+(aq)
To determine the presence of Fe3+, 0.10 M of KSCN was used. The product was a blood red solution. The reaction’s balanced equation is:

Fe(NO3)2 (aq) + 2 KSCN (aq) Fe(SCN)2 (aq) + 2 KNO3 (aq)

It has a net ionic equation of:

Fe3+(aq) + SCN-(aq) → FeSCN2+(aq)
1.00 M HCl, meanwhile, was used to determine the presence of Ag+ in the resulting supernate. This resulted to formation of white precipitate. The reaction has a balanced equation of:

Ag+(aq) + Cl-(aq) → AgCl(s)

The table below shows the summary of the observed confirmatory test results:

Table 1. Data for Iron(II)-Silver Ions System

Test Reagent| Visible Result|
K3Fe(CN)6| Prussian blue|
KSCN| Blood red|
HCl| White ppt|

The results observed on the three separate confirmatory tests done proved the existence of the system reaching equilibrium and that the reaction between iron and silver did not reach...