I'm trying to wrap my head around this one.
Oxidation of Iodide to Iodine; Spectroscopic measurement of TriIodide ion.
IO3- + 5 I- + 6 H+ --> 3 H2O + 3 I2 (standard)
H2O2 + 2 I- + 2 H+ --> 2 H2O + I2 (unknown)
I- + I2 --> I3-
STANDARD:
Put into a clean 250 mL volumetric flask exactly . 0.90 ml
of 1.00 mM iodate STANDARD.
Add an excess of 1M KI and 1M Sulfuric Acid and let stand for 5 minutes. Dilute to volume.
UNKNOWN: Pipet into a clean 250 mL volumetric flask 1.00 mL of your UNKNOWN and dilute to volume with distilled water.
Put into a clean 250 mL volumetric flask exactly . 0.90 mL
of this diluted H2O2 UNKNOWN.Add an excess of 1M KI and 1M Sulfuric Acid and let stand for 5 minutes. Dilute to volume (250 mL). Measure STANDARD and UNKNOWN spectroscopically at 360 nm using the same cuvet throughout.
% Transmission of BLANK.... 98.3 %
% Transmission of STANDARD..... 58.7 %
% Transmission of UNKNOWN... 51.7 %
(g) Absorbance of STANDARD.....… ___________________
(h) Absorbance of UNKNOWN...… ___________________
(i) Molarity of original UNKNOWN... ___________________ M
Okay I get the absorbance questions and how to do (i) but what Concentration do I use for C1 in the Beer's Law equation??
Side note -- When ever I ask my Chem teach a question he responds what's the problem? Is this obvious am I missing something??