answers needed ASAP Consider the fol nalys whi e.) You have two LED s, a red and

Question

answers needed ASAP

Consider the fol nalys whi e.) You have two LED s, a red and a green. Which LED should you use for this analysis and why? Complementary Wavelength in nm) Ultraviolet Violet 380-435 Yellow-green Blue 436 480 Yellow 481-490 Greenish-blue 491-500 Bluish-green. 501-560 Yellowish green 561-580 581-595 Yellow Green-blue 596-650 Orange Blue-green Red Near Infrared f) A standardized stock solution was prepared by dissolving 0.0593 grams of KMno4 (Mw of KMno4 is calculated to 34 g/mol)) in water and diluting to 500 ml. The molarity of the stock solution be g. Four solutions of KMno4 were prepared from the stock solution above. The preparations are given in the following table: Given A 2- log(% T) Absorbance Final of Final Solution Vol Stock (/ml) Volume Concentration Transmittance (M) (/ml) 74.8 100.00 10.00 100.00 54.0 100.00 52.0 100.00

Explanation / Answer

KMnO4 used is in the wave length of 525 nm. KMnO4 used is blue in color and hecne the raange is Red 651-780 whose complimentary colors are blue and green.

2. Molarity = moles/L = (0.0593/154)/0.5 = 0.00077M

3.

Concentration =0.00077M

From C1V1= C2V2, C2= final concentration, C1=0.00077M, V1= volume of stock solution

A= Absorbance

Solution 1 : C2= 0.00077*10/100 = 7.7*10-5 , A = 2-log (74.8)= 0.126

Solution 2 : C2= 0.00077*15/1000 = 0.000116, A= 2-log (64.2)= 0.192

Solution 3: C2= 0.00077*20/100 = 1.54*10-4,   A = 2-log (54)= 0.270

Solution 4 : C2= 0.00077*25/100 = 0.000193, A =2-log (52)= 0.283

the plot of Absorbance vs concentration is shown in the graph, whose slope is 1595

from A= ebC

eb= 1595

e =molar absorptivity = 1595 /Cm.M

for A= 0.236

x = concentration = 0.236/1595= 0.000148 M

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.