Food Dye With Bleach

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Name Lab Section Course Code Drawer Number Date The Reaction of a Food Dye with Bleach Introduction The goal of this experiment was to determine the reaction of a food dye with a bleach, x. It was hypothesized that x would be in 1st order with respect to the dye. By examining the slope of the line, the concentration vs. time graph was used to determine the value of x. It was hypothesized that a graph of In[A]versus time would produce a linear line; the order of x with respect to [A] would be first order. The order of x with respect to absorbance (A) can be determined by plotting a graph of [A] vs. time, In[A] vs. time, and 1/[A] vs. time. The order of x is considered to be zeroth order if the graph of [A] vs. time is linear, and first order…show more content…
Second, 10.00 ml of the blue dye was poured into the 100.0 ml beaker and stirred for 2 – 3 seconds. The time taken by the solution to turn to colorless was measured with the aid of a stopwatch. The aim of this exercise was to determine the mixture that turned colorless in 15 minutes time. The data was recorded as shown in Table 2. Absorbance versus Time Measurements: The absorbance was set to 0 Abs while the spectrometer was set to ʎmax (from Part A). In Part B, 1.00 ml of the solution was mixed with the Blue dye in the beaker and half-way covered with a cuvette. Concurrently, the Spectronic 20 was blanked with water. The processes detailed above were repeated, each at a time. The absorbance values were recorded for 11 minutes. Results Part A: Table 1: Absorbance (A) vs. Wavelength (ʎ)…show more content…
From equation [2], the Absorbance, Abs = ebC. Thus, C = Abs/e*b e*b = 1 dm ×100cm/dm × 1.38 × 〖10〗^5 cm^(-1) M^(-1) L. =1.38 × 〖10〗^7 C=Abs/(1.38 × 〖10〗^7 ) C=(2.507)/(1.38 × 〖10〗^(-3) )=1.82×〖10〗^(-7) M The value of K: From the calculations above, the rate law equation [3] reduces to: Rate = K_observed 〖[Blue dye]〗^x Where Kobserved = K [NaoCl]1 and Kobserved is the experimentally obtained value of K = 0.1963 M-1 min-1. Thus, Rate =0.1963/(M.min) 〖[Blue dye]〗^x From Figure 3, it was established that the reaction was in first order. Thus, the overall rate law equation reduces to: Rate = 0.1963〖M^(-1) min^(-1)⁡× [Blue dye]〗^1 Rate = 0.1963M^(-1) min^(-1)⁡× 〖[1.82×〖10〗^(-7) M]〗^1 Discussion From Part B, the optimal reactants combination selected for Part C was 1.00 ml of Clorox + 40 ml of Blue dye because the mixture turned colorless in ~15 minutes (15:32.58 s). In addition, the graph of In[A] versus time was linear. Thus, the order of x with respect to [A] was first order. In effect, the hypothesis was confirmed. In contrast, plots of Abs. versus time and 1/A versus time yielded exponential curves. The linearity of the curve of In(A) versus Time had a correlation coefficient of 0.6327. Tacitly, the deviation from expectations, assuming an ideal, perfect experiment with R2 = 1, is attributed to experimental errors (Trimm

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