Chemistry 103/113 Laboratory
	This Week
Answer Keys Gen Chem Lab Periodic Table	· Expt 6: Photochemical Blues (week 3) o Report due tomorrow · Quiz 4: Expts 4, 8
	Next Week
	· No lab meeting/nothing due, enjoy the holiday
	Next Time
	· Expt 7: Exploring Nanotechnology
	Notes for Today
	Photochemical Blues (Week 3) · Overview: o Synthesize/purify K3Fe(C2O4)3^.3H2O (Week 1) o Qualitative tests for K^+, Fe^3+, C2O4^2- (Week 2) o %Fe photoreduction assay (Weeks 2,3) o Make blueprints (Week 3) · Quantitative Analysis of Fe^3+: o Problem: What is mass %Fe? o What has happened so far: Dissolved known mass of green solid in acetic acid (Fe^3+released) Exposed to sunlight to convert Fe^3+ to Fe^2+ Fe^2+ precipitated as FeC2O4.2H2O o What you must do today: QUANTITATIVELY collect FeC2O4^.2H2O(s) rinse thoroughly with acetone weigh the FeC2O4^.2H2O recovered find mass of Fe^3+from moles FeC2O4^.2H2O recovered · How Blueprinting Works: o Coat paper with ferricyanide (safe!) and K3Fe(C2O4)3^.3H2O mixture o Put opaque object or drawing over paper and expose to light § Fe^3+ -> Fe^2+ § Why is light necessary? § Fe^2+ reacts with ferricyanide to form a blue compound o Fix the blueprint to wash away unexposed photosensitive chemicals · Safety Issues o Splash hazard. Goggles required. o Acetone is flammable o Collect acetone filtrates in waste recovery jug. o Gloves recommended during blueprinting.