jpark9
Posts: 1
Joined: Wed May 14, 2014 1:52 am
Occupation: Student" 8th grade

Presto! From Black to Clear with the Magic of Photochemistry

Postby jpark9 » Wed May 14, 2014 1:57 am

http://www.sciencebuddies.org/science-f ... #procedure

This Link ^here^ is what I am doing for my science fair project, and I have a few questions.

First, will this experiment work without the ammonia and oxalic acid?

Second, why is it important to learn how light can affect the rate of a chemical reaction?

Please help its due in 3 days :(

tdaly
Former Expert
Posts: 1415
Joined: Sat Nov 08, 2003 11:27 pm
Occupation: Planetary Scientist

Re: Presto! From Black to Clear with the Magic of Photochemi

Postby tdaly » Fri May 16, 2014 9:10 am

Hi jpark9,

No, the experiment will not work without ammonia and oxalic acid. Take a look at equation 1 in the background information. If you took out ammonia and oxalic acid, then the only reactant that would be the iodine. So, the iodine would not convert to iodide.

Photochemical reactions are very important in Earth's atmosphere, where they are responsible for breaking up ozone molecules. The free oxygen released in the process can bond with hydrogen to make hydroxyl radicals. Photochemical reactions are also important in the atmosphere of Titan, one of the moons of Saturn. On Titan, photochemical reactions produce organic compounds. Photochemical processes are also important in manufacturing. Check out this Wikipedia article for more details:

http://en.wikipedia.org/wiki/Photochemical_machining
All the best,
Terik


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