The following reaction including crystal violet and also sodium hydroxide (expressed as its network ionic equation):

C25H30N3+ + OH- --> C25H30N3OH


will be investigated in this activities activity. The rate regulation of the reaction is

rate = k α β .

When >> , equation 1 i do not care

rate = k* α, whereby k* = k β

which is a psudeo-rate law that the reaction. The value of β and also k might be obtained by differing the .

This laboratory task is based upon investigation 11 in your AP chemistry lab manual; thus, it provides some relevant background because that the complying with prelab questions and this activities activity.

1. How might you usage a colorimeter to measure up the as a duty of time ? include its basis / rationale.

You are watching: Crystal violet + naoh balanced equation

2. How could you use graphical evaluation of the coming before data (do not usage the rate of a reaction) to recognize the value of the parameters

a. α

b. β and also k

in equation 1 (shown above) ?

3. What must be the duration of data collection period (as a percent that the early stage concentration the the dye) ? incorporate its basis / rationale .

4. What is the communication / reason of the (above) psudeo-rate regulation ? what is the experimental problem for the psudeo-rate regulation to be precious ?

review (i) use of the colorimeter / wavelength an option / calibration curve indigenous your previously Beer"s legislation lab, (ii) how to settle solution preparation difficulties ! also, the syntax / protocol in making use of MS Excel to generate the calibration curve and also to transforn your (i) absorbance to concentration, (ii) concentration to organic log that the concentration, and (iii) concentration to reciprocal concentration. As appropriate, incorporate sketches / display screen shots to clarify your solution and use in-text citation.


identify the rate law (i.e. Value of α & β, & k, in equation 1) because that the reaction entailing cyrstal violet and also sodium hydroxide. recognize the rate regulation (i.e. Value of k & α in the listed below equation) of the burn of a candle

rate = k (mass of candle) α ; devices of rate = fixed / time.


colorimeter, cuvette, data arsenal device, clock (provide your own)

decision violet (Cv+; ~ 25 µM); NaOH (~ 125 mM); water; 100 mL volumetric flask

pipet; candle, electronic balance


crystal violet reaction

part 1: prepare crystal violet and sodium hydroxide solutions; re-publishing solutions amongst 2 groups at a table. When the sodium hydroxide solution could be made in a solitary step, recommend prepare the decision violet systems in two steps. As such, you must be familar in doing these calculations prior come the lab.

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part 2: conference data to generate calibration curve for decision violet

evaluation Beer"s legislation lab use of colorimeter & that is calibration determine ideal λ in the colorimeter to usage in this experiment

part 3: gather data to determine the reaction"s rate law

quickly mix services of Cv+, NaOH, and water right into the cuvette, then put it into the colorimeter

trail 1: 3 mL Cv+, 2 mL NaOH, 0 mL water

trail 2: 3 mL Cv+, 1 mL NaOH, 1 mL water

start timer upon mix the chemicals. Document absorbance in ~ 30 secs intervals because that 30 minute (or absorbance

burning a candle

student architecture

Content of lab report <33 points>

graphical analysis <18 points>

fading that cyrstal violet <4 graphs & calibration curve; 3 clues / graph = 12 points> burn a candle <3 graphs; 2 points / graph = 6 points>

calculation of price law, i.e. Parameters in the ideal rate law; to express to preceding graphs <15 points>

burning a candle <3 points> fading of decision violet <12 points>


CV lab trouble-shooting article

lab activity source (examples):site 1 & site 2

youtube video: data analysis hint

simulations: *.cdf (requires cdf player plugin) or *.nb (requires mathematica): guided inquiry into determining (i) wavelength to measure up absorption (ii) family member and also for valid use of psudeo rate law approximation, and (iii) expression of data collection.