Electron Configuration and the Formula for Photosensitive and Blue Compound

Refer to the file

Cyanotypes

The use of cyanotypes (blueprints) dates back to the 1840’s when Sir Jon Herschel discovered the light sensitivity of certain iron salts. To make a cyanotype paper is treated with a solution of potassium ferricyanide [K3Fe(CN)6] and ferric ammonium citrate to produce the photosensitive compound, iron(III)hexacyanoferrate(III) Fe[Fe(CN)6]. When paper coated with this chemical is exposed to light, the light reduces the ferric ion (+3) to ferrous ion (+2) and ferrous ferricyanide Fe3[Fe(CN)6]2 is produced, which is an insoluble deep-blue compound called Prussian blue. If you were able to purchase the cyanotype kit and get it in time please follow the instructions on your kit. Remember to let the paper dry after coating and before exposing it to visible light.

1. Explain why transition elements are special and make the electron configuration for element 21 to 30.

2. Make the electron configuration for iron Fe2+

3. Make the electron configuration for Fe3+

4. Write the formula for the photosensitive compound.

5. Write the formula for the blue compound. What is its name? Explain why it is blue (what is the process for energy absorption).

6. What are other processes for energy absorption in inorganic compounds?