Is chloride ion or water a stronger ligand?

Clueless

Is water or ammonia a stronger ligand?

Clueless

Is ammonia or ethylenediamine a stronger ligand?

Clueless

I don't really get the idea of ligands; I definitely won't get strenght of ligands. I know ligands replace other ligands...

P.S I know that it is an ion or molecule that binds to a metal to form a complex. Unfortunately, my lab manual does not explain strenght of ligands.

Look in your text for the chapter on coordination compounds. The freshman text I have by Whitten, Davis, Peck lists this order for strengths of ligands with regard to crystal field theory.
I^- <Br^- <Cl^- <F^- <OH^- <H2O <(COO)2^2- <NH3 <en <NO2^- <CN^- where en is ethylenediamine. I hope this helps.

Thank you Dr.Bob... my problem though is that I do not see why it is stronger. For example my lab manual asks why it would be stronger. I just have no clue why? I wrote for the first question that chloride ion is bigger than water molecule (not sure if correct); for the second question, I wrote that ammonia is the same as water molecule(again, not sure why... just guessing) I have finals today (6pm on the dot), I'm afraid a similar question might be on test in lecture. Here is the list of the questions... (I'll look at text again to see where I misread)thx

As far as I know there is no "theory" that goes along with which is weaker vs which is stronger. The table I listed in my last response is based on the spectrochemical series of colors. The order I listed is determined by what colors are formed by the complex(s); i.e., a coordination complex is formed, the absorption of light is mesured (even into the ultraviolet) and the order is determined from the wavelength absorbed. More energy is in the UV and less energy in the red and orange. Your original post asked, "Is chloride ion or water a stronger ligand?" The second question was similar and the same for the third. No where did the problem ask WHY. I have looked at my references at home and I can't find a WHY. I think it is a combination of size, electronegativity, dipole moments, and number of connecting sites on the ligand (en, for example, is a bidendate instead of a monodentate), just to name a few, but there may be others. That means memorizing the list from top to bottom or the reverse. I don't find anything that connects size, EN, dipole moment, etc to the strength of a ligand.

Good luck on your finals.

I apologize for any confusion earlier. It seems that the concept of ligand strength can be quite complex and may not have a straightforward explanation. From the information I have, the strength of a ligand is determined by various factors such as size, electronegativity, dipole moments, and the number of connecting sites on the ligand. Unfortunately, there may not be a clear explanation as to why one ligand is stronger than another. It may be necessary to memorize the order of ligand strength from a reliable source or consult with your instructor for a more detailed explanation. Best of luck with your finals!

Determining the strength of ligands is a complex topic that involves various factors such as size, electronegativity, and other properties of the ligand. It is not always straightforward to understand why one ligand is stronger than another. In the context of coordination compounds, the strength of the ligand refers to its ability to bind to a metal ion and form a stable complex.

The strength of a ligand can be experimentally determined by studying the absorption of light by the resulting complex. This is known as the spectrochemical series. A ligand that absorbs light at shorter wavelengths (higher energy) is considered to be stronger, while a ligand that absorbs light at longer wavelengths (lower energy) is considered to be weaker.

In the absence of a specific theory or explanation, the order of ligand strength can often be memorized from a given list or table. For example, the order provided in your previous response was based on the spectrochemical series observed for certain ligands.

To understand the specific reasons why one ligand is stronger than another, it would require a more detailed study of coordination chemistry, including concepts like crystal field theory or ligand field theory. These theories take into account factors such as size, charge, and electron donating/withdrawing ability of the ligand in determining its strength.

In summary, the determination of ligand strength is a complex topic that involves several factors, and it may require a deeper understanding of coordination chemistry principles to fully comprehend the reasons behind ligand strength.