CHEM 1111 Lecture Notes - Lecture 14: Potassium Dichromate, Reaction Rate, Reagent

41 views2 pages

lemonfrog498

8 Nov 2014

School

Department

Course

Professor

For unlimited access to Class Notes, a Class+ subscription is required.

Document Summary

Calculations: see attached sheets, the data shows that the reaction is first order with respect to the dichromate. The units are s-1 because in a first order reaction rate (m/s) is equal to k times the concentration of the reactants (m). Therefore k must have units of s-1: rate constant: (1 / m120) = kt + (1 / m0) for t = 120s so, k = ((1 / m0) (1 / m120)) / 120. Questions: the rate of the reaction would be altered if the initial concentration of potassium dichromate in solution were changed. This could be done by changing the amount of 0. 0196 m potassium dichromate which is added to the erlenmeyer flask. Incorrectly measuring the amounts of solute and solvent could affect the experiment because not enough of the reagent would cause the reaction to not reach completion.

Related Questions

1. The rate law for a certain reaction is second order with respect to one of the reactants, R. Suppose you study this reaction, observing the absorbance of light at the analytical wavelength for R, and record the data with respect to elapsed time. Also suppose that the concentrations of all the other reactants are in large excess, and that A is the only colored species involved. Explain which absorbance function, A, ln A, or 1/A, would yield a straight-line graph when plotted against elapsed time.2. Suppose that in the reaction Q + R ? P, only the product, P, is colored.(a) What happens to the absorbance at the analytical wavelength for P of the mixture as the reaction progresses?(b) Suppose you do an experiment involving this reaction in which Q is present in large excess of R. If this reaction is first order with respect to R, would the graph of ln A (for P) versus time be a straight line? Briefly explain.Please help!

yellowspider453

Can someone help me with these calculations? I am very confusedwith how to do them. The lab is based off of this: http://course1.winona.edu/jfranz/lab/chem%20213%20lab/Exp2_CV_Kinetic_Study.pdf.Also above and below is my data.

is my data.

Concentra Absorbance With Respect to Crystal Violet Graph of absorbance versus concentration using the average absorbance values, (see manual introduction for graph requirements and Excel Tutorial posted on Sakai for assistance on making a graph.) Conversion of absorbance readings to concentration values for kinetics trials, Graph of [CV] versus time for first three kinetic trials. (Put all three trials on the same axes.) Graph of ln[CV] versus time for first three kinetic trials. (Put all three trials on the same axes.) Graph of 1/[CV] versus time for first three kinetic trials. (Put all three trials on the same axes.) Comparison of linear fit of the reaction orders to one another to determine order of reaction with respect to crystal violet. Graph of appropriate relationship between [CV] and time for last three kinetic trials. (Put all three trials on the same axes. See Excel Tutorial on Sakai site for directions.) Determination of the concentration of OH' in the reaction tube immediately after mixing with crystal violet in Parts 2 and 3 of the experiment. Determination of order of reaction with respect to [OH']o using the ratio of the slope for best fit of first three kinetic trials to the slope for the best fit of the last three kinetic trials, as shown here (slopes may be positive or negative whereas k is always positive): Recall that k' = k[OH f - you are solving for "n". Calculate the rate constant "k" for each kinetic trial, the average rate constant, and the standard deviation for rate constant. Include each of the values you will address in the Discussion. written in paragraph-form. describe each of the following: Does the rate of the reaction change as the reaction progresses? Support your conclusion. What is the order of the reaction with respect to each of the reactants (both crystal violet and sodium hydroxide)? Support your conclusions. What was the percent error in the order of reaction with respect to NaOH from your results? Is it significant (large or small compared to the value)? Support your conclusion. Write the rate law for the reaction and identify the value for the constant. How do you quantify error for each part in this experiment? To what sources do you attribute error for each part of your experiment? Explain how the suspected sources could contribute to the magnitude and direction of the error.

CHEM 1111 Lecture Notes - Lecture 14: Potassium Dichromate, Reaction Rate, Reagent

Document Summary

Get access

Related textbook solutions

Chemistry: Structure and Properties

Basic Chemistry

Principles of Chemistry Molecular Approach

Principles of Chemistry Molecular Approach

Chemistry: Structure and Properties

Chemistry: A Molecular Approach

Chemistry: A Molecular Approach

Principles of Chemistry: A Molecular Approach

Chemistry: The Central Science

Related Documents

CHEM 1C Lecture Notes - Lecture 15: Potassium Dichromate, Cuvette, Spectrophotometry

CHEM 1102 Lecture Notes - Lecture 3: Chromate And Dichromate, Nitrogen Dioxide, Reaction Rate Constant

CHEM 201 Lecture Notes - Lecture 29: Reaction Step, Protein Kinase B, Rate Equation

Related Questions