Reaction of Food Dye - Grade: A- PDF

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Reaction of Food Dye

Reaction of Food Dye Brian Chen California State University, Los Angeles 9/15/2020

Reaction of Food Dye

Introduction Chemical kinetics is the study of the speed that chemicals and physical properties occur. This chemical reaction is the amount of the product changes in each time defines the amount of the reactant the disappears. Bleach chemicals are usually the solution chlorine, hydrogen peroxide, and sodium perborate. The oxidizing agents can dissolve most living substances. With this experiment, the oxidizing agent bleach will be used to breakdown the chemicals of food dye. In this experiment, our action is to find the rate of reaction of bleach with our food dye. Kinetics in chemistry allows us to study the chemical reactions speed in our experiment. The rate of reaction is described as the speed at which a chemical reaction proceeds. Our main equation of the reaction of bleach and food dye can be A+B C+D. The ability to study this experiment will introduce us to the knowledge of chemical thermodynamics, which grasp an important role of chemistry. Purpose The purpose of this research includes 

Solve for the rate constant for the reaction of this experiment

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Using the Beer law to determine bleach and dye concentration

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Find the rate law for bleach and dye in each reaction.

Materials Bleaching agent solution (NaOCl), food dyes, volumetric flasks, UV/Vis spectrometers, Theory Principles

Reaction of Food Dye The theory principles in this experiment allows us to solve for the rate and mode of the products’ state, and the reactants’ speed of disappearance. With this information, we can find the reaction involved in the molecular degree. This chemical reaction happens through the steps shown below. Rate laws consisting of one reactant The rate law is: RateRXN = -(β[E])/βt=k[E]^x or In[E]=-kt + In[E]0 E → products t → time The value of x changes directly impacted to the order of the reaction. That is, when the order is =0,1,2,3. Beer Law To be able to use the rate law in absorbance values to concentration, we need to convert [dye]m[bleach]n to a new formula abs = ε l [dye] this event will allow us to use molar absorptivity ε and the path length of light through solution l to find absorption Pseudo rate orders

Reaction of Food Dye The reason for this equation if to find reactions with more than one reactant. This principle allows varied reactions and reaction orders. This idea gives us the ability to find one reactant to be used in excess, so we can maintain the concentration of the chemicals throughout the reaction. Pseudo rate order is: RateRXN = kobs[E]x Where k(obs) are the maintained k K(obs)= k[B]^y =a constant Procedures 

Use the serological pipet to deliver between 9.00 mL of dye into the vial

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Move the vial into the spectrophotometer

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Drop the magnetic bar into the vial

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Use the 1 mL syringe to deliver 1.00 mL of bleach into the vial (to make up the volume to 10.00 mL)

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Immediately cover the vial with the black lid to start the measurement.

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When the simulation has completed, select a plot (abs versus time, ln(abs) versus time, 1/abs versus time) that is most useful for determining the order of the reaction and the pseudo rate constant k'. When you are satisfied with your kinetic trace, print it out. Make sure to include your name, Andrew ID, and a descriptive title, which will identify your experiment (i.e. 9.80 mL dye with 0.20mL 0.090M bleach).

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I will test the Beer’s law ad 3.06X10^-5 concentration of the dye to use on the experiments on the kinetics of food dye.

Reaction of Food Dye 

The results of the information will find the reaction order determination.

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An alternative is the Beer’s law does not give results, then another concentration of the experiment will act to find the reaction order of this experiment.

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Since there are more than one reactant in this experiment, we must find the excuess usage of one reactant which results in using the pseudo rate principle.

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Use the dye as a limiting reactant in this chemical reaction, and the bleach is placed in excess to notice the change in color during the test

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Make sure that the spectrometer is set to zero

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Use the serological pipet to pour nine milliliters of dye into vial

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Place vial into a spectrometer and place in the magnetic bar

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Pour one milliliter of bleach into vial and cover

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Collect ,observe and record the results.

Results To show our results, we graphed the absorbance (y axis) vs time for bleach concentration (x axis 0.09M)

Reaction of Food Dye

The next step is to show a graph of ln absorbance (yaxis) vs time of bleach concentration ( x axis 0.09M)

The next step is to show absorbance (y axis) and double the bleach concentration (x axis 0.180M)

Reaction of Food Dye

Now we have to do ln absorbance again (yaxis) vs time for double the bleach concentration (axis 0.180M)

Last we show a graph 1/absorbance (y axis) vs the time of the bleach concentration of 0.180M ( x axis)

Reaction of Food Dye

Discussion (a) The time, absorbance, volumes of the reactant were measured with various dye concentrations, and the results are summarized below. Volume of dye solution

9.00ml

Concentration of bleach solution

0.090

Volume of bleach solution

1.00 ml

(b)The initial concentration of 9.00mL volume of dye in 10.00mL solution is 3.06x10^-5M. The initial concentration of 0.090M bleach in 10.00mL is 9.00x10^-3M. this allowed us to start our experiment with the basic information of chemicals. (c)The pseudo rate constant is made through the case that the reaction is first order. The pseudo rate order and rate law correlates for the reaction allows us to find and accurate stoichiometry. Since we our able to find precise results, we have to use another set of results

Reaction of Food Dye in the same laboratory we need. Using our formulas given to us, we can find the order of reaction. (d) Knowing , k(pseudos) =k[bleach]n = k[9.00x10^-3] = 0.243M/s we now have to have the bleach concentration doubles and the slope would be able to be found. K(pseudos) =k[bleach]n = k[1.80x10^-2] = 0.4860M/s then dividing the belach by two reduces the rate also by two, and the reaction of the first order would be found.

(e) For the first-order reaction: In([dye]) =-k’t + In([dye]0) or In (absorbance)= -k’t + In(absorbance)0. From the graph In Abs=-2.43e-1t +5.07e-2 From Beer's law In Abs =ε l[dye]. Rate remains constant Rate law: k[bleach]n[dye]

Reaction of Food Dye Kpseudo=slope of the graph K= 2. 43e-1 With our equation and graphs when bleach concentration is increased, the rate of the reaction will increase with it. K= 0.243M/s

(f) The rate of change of absorbance is directly proportional to the rate of change in concentration to dye. Abe = el(dye) Knowing that A or abs = k Abs= -2.430(0.090)=-0.2187 Abs= -2.430(0.180)=-0.4374 And mean is = -0.32805 we can find -0.32805/3040X10^-5 = ε l -96480529412M^-1 (g) To find the rate constant for the reaction of the dye with bleach, we will write the rate law for the reaction. R= 2.45 (dye)^0.0086(bleach)^2

Rate law = -K (A)^m(B)^n 0.018 = -k (a)m(0.090)n 0.072= -k(a)m(0.180)n

Reaction of Food Dye

Divide 0.072/0.018 = -k(a)m(0.18)n/-k(a)m(0.09)n 4=2n 2^2=2^n n=2 Given the results, the equation is in second order K=-2.430 Rate law = -K (A)^m(B)^n 0.072=2.43(3.4X10^-5)^m (0.18)^2 (3.4X10^-5)m = 0.91149 M=0.0086 With dye 0.0086 R=2.43(3.40X10^-5)^0.0086(bleach)^2

Conclusion To conclude the experiment using Rate laws consisting of one reactant, beer’s laws, and pseudo rate first order allowed us to study the chemical reactions speed in our experiment. The reactions are in the first order reaction, and the experiment portrayed that a diluted bleaching agent decomposes food dyes in less than twenty seconds. Following the lab procedures and background from the website allowed us to find no errors and precisely

Reaction of Food Dye annotate our results from our experiment. The reaction had a rapid rate that the concentration of the reactants was measured for less than twenty minutes....