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(2 pt Label on Volumetric Volume of 0.5000 M Molarity of Flask cobalt (III) chlo

ID: 496365 • Letter: #

Question

(2 pt Label on Volumetric Volume of 0.5000 M Molarity of Flask cobalt (III) chloride Known Co hexahydrate stock Solution (M solution added (mL Known Co2 Solution 1 Known Co Solution 2 8.000 Known Co. Solution 3 6.00 Known Co Solution 4 4.00 Using the information in your lab manual to calculate the concentrations of the diluted solutions and copy the calculated results into Table 1 in your lab manual. (Show your work for at least one calculation.) 2. (1 pt.) The concentration of Co in the sample is directly proportional to the of light by the cobalt sample. d. emission c, absorbance b. reflectance a. transmittance

Explanation / Answer

1. concentration of Co2+ in solution

With the total volume of solution = 10 ml

Table                          

Solution                     0.5 M stock solution (ml)            molarity of Co2+ (M)

    1                                            10                                            0.5

    2                                              8                              0.5 M x 8 ml/10 ml = 0.4                                             

    3                                              6                              0.5 M x 6 ml/10 ml = 0.3                                             

    4                                              4                              0.5 M x 4 ml/10 ml = 0.2                                             

2. The concentration of Co2+ in the sample is directly proportional to the -------- of light by the cobalt sample,

c. absorbance

This is according to the formula,

Absorbance = molar absorptivity x path length x concentration