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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: dhouse0610 on December 05, 2009, 08:29:22 PM

Title: what causes the dark color that is formed when AgCl is exposed to light?
Post by: dhouse0610 on December 05, 2009, 08:29:22 PM

what causes the dark color that is formed when AgCl is exposed to light?

Title: Re: what causes the dark color that is formed when AgCl is exposed to light?
Post by: dhouse0610 on December 06, 2009, 02:34:15 PM

I am writing a lab report and there is a question that asks what causes the dark color  that is formed when AgCl is exposed to light?

I have looked around on the internet but I cannot seem to find the reason as to why. I think that it is due to the photodecomposition of AgCL but I am not sure.

Could you please help?

Title: Re: what causes the dark color that is formed when AgCl is exposed to light?
Post by: baboom on December 06, 2009, 03:10:16 PM

Hi,

The dark colour is the result of the photodeomposition of the AgCl in the precence of organic compounds. The purple colour is elemental silver.

Title: Re: what causes the dark color that is formed when AgCl is exposed to light?
Post by: baboom on December 12, 2009, 08:49:54 PM

Standard silver nitrate solution and the silver chloride precipitates formed were protected
from light at all times because silver chloride decomposes according to:
AgCl---> Ag(s) + ½ Cl2 (g)