Photochromic glass used for sunglasses darkens when exposed to bright light and becomes more transparent again when the light is less bright. The depth of colour of the glass is related to the concentration of silver atoms. The following reactions are involved
Reaction 1 Ag+ + Cl- reverse sign Ag + Cl
Reaction 2 Cu+ +Cl arrow cu+2 + Cl-
Reaction 3 Cu+2 + Ag arrow Cu+ + Ag+
Which statement about these reaction is correct?
a) Cu+ and Cu+2 ions act as catalysts
B) cu+ ions acts as oxidising agent in reaction 2
c) reaction 2 is the one in which light is absorbed
D) Ag+ ions are oxidised

Question

Photochromic glass used for sunglasses darkens when exposed to bright light and becomes more transparent again when the light is less bright. The depth of colour of the glass is related to the concentration of silver atoms. The following reactions are involved
Reaction 1 Ag+ + Cl- reverse sign Ag + Cl
Reaction 2 Cu+ +Cl arrow cu+2 + Cl-
Reaction 3 Cu+2 + Ag arrow Cu+ + Ag+
Which statement about these reaction is correct?
a) Cu+ and Cu+2 ions act as catalysts
B) cu+ ions acts as oxidising agent in reaction 2 
c) reaction 2 is the one in which light is absorbed 
D) Ag+ ions are oxidised

abmon98 · Answer

http://papers.xtremepapers.com/CIE/Cambridge%20International%20A%20and%20AS%20Level/Chemistry%20(9701)/9701_w09_qp_11.pdf

abmon98 · Answer

Question 11