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December 21, 2014

Search: chemistry- absorbance & transmittance

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chemistry- absorbance & transmittance
An unknown was prepared with the concentration of 0.000120 M. A Beer's Law plot was prepared using the absorbance values from standard solutions of ASA and a line drawn through all the points passed through the origin with a slope of 1750.0 M–1. The expected absorbance and %T ...
February 16, 2007 by christine

Chem
I'm confused with Determining the concentration of a soution: beer's law lab. 1.Explain why pure water is set for a transmittance of 100%. - I believe the pure water is set for a transmittance of 100% in order to for a tranmission relative to water 2. Explain why red light was...
February 22, 2011 by Unknown

science
a)why do chemist prefer to read/ record the absorbance, rather that the percent transmittance, of light when analyzing a sample having a visible color? b) three parameters affect the absorbance of a sample. Which one is the focus of this experiment?
January 31, 2011 by joe

chemistry
1. Why Beer's law is expressed in terms of absorbance instead of transmittance? 2. What is the significance of spectral scanning? 3. What is the importance of the baseline?
September 14, 2007 by smiley

chemistry
how do I plot absorbance vs concentration and transmittance %T vs concentration on the same graph??
November 6, 2010 by Vivian

Please help with Chemistry?????
A standard solution with a FeSCN2+ concentration of 1.55x10^-4M has a percent transmittance (%T) of 18.8%. Another solution of unknown FeSCN2+ concentration has a percent transmittance of 44.8%. A) Calculate the absorbance (A) of each solution. B) Using the absorbances ...
February 26, 2014 by Dan

Chemistry
A standard solution with a FeSCN2+ concentration of 1.55x10^-4M has a percent transmittance (%T) of 18.8%. Another solution of unknown FeSCN2+ concentration has a percent transmittance of 44.8%. A) Calculate the absorbance (A) of each solution. B) Using the absorbances ...
February 26, 2014 by Dan

chemistry
An unknown was prepared with the concentration of 0.000331 M. A Beer's Law plot was prepared using the absorbance values from standard solutions of ASA and a line drawn through all the points passed through the origin with a slope of 1646.3 M–1 . The expected absorbance and %T...
May 14, 2007 by jared

Honors Chemistry
At what wavelengths do Cr(III) ions absorb the maximum amounts of light? Look at your color wheel. What color is Cr(III)? It will absorb the complement of its color. You may have a graph of absorbance vs wavelength for Cr(III). If so, the maximum absorbance (in th visible ...
October 16, 2006 by Anonymous

Chemistry
You are measuring the concentration of Fe2 in a sample by measuring the absorbance of its complex with ferroxine. Your sample, measured in a 1.00-cm pathlength cuvette, has an absorbance of 0.347 while the reagent blank in the same cuvette has an absorbance of 0.040. What ...
April 20, 2013 by Shai

chemistry class
i have a Chemistry lab (level 2) final exam soon. our teacher told us that we would have % transmittance problems, can someone show me an examples (maybe from an online test) or a made up one, of what i might expect to find on my chemistry lab final? like an examples of a % ...
December 1, 2010 by jes

chemistry
The standard solution of FeSCN2+ (prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN) has an absorbance of 0.510. If a trial's absorbance is measured to be 0.250 and its initial concentration of SCN– was 0.00050 M, the equilibrium concentration of SCN...
April 9, 2008 by Jason

Chemistry
How would you get the concentration(ppm) of a sample from absorbance? Absorbance of standard = 2.55 Absorbance of sample = 2.31 Wavelength of machine 345nm slit lenght = 1cm time = 2s The metal being tested is Copper and the concentration of the standard is 8ppm.
March 7, 2012 by Lora

chemistry
The standard solution of FeSCN2+ (prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN) has an absorbance of 0.520. If a trial's absorbance is measured to be 0.275 and its initial concentration of SCN– was 0.00060 M, the equilibrium concentration of SCN...
April 14, 2008 by david

Chemistry
Help! If I have 0.0031 absorbance/sec, how would I convert this to absorbance/minute? Thanks
October 22, 2013 by Anon

Chemistry
There is a large [Cr2O7]-2 absorbance observed at 360 nm. Why can this wavelength not be used instead of the smaller absorbance at 440 nm?
February 23, 2012 by ella

College Chemistry Lab
Suppose that a 2.50x10^-6M solution of red dye No. 2 had an absorbance of 0.585 at its wavelength of maximum absorbance. A second solution of red dye No. 2 is too concentrated to read its absorbance so 5.00 mL of the concentrated dye solution was diluted with water to a volume...
March 16, 2010 by L**

chemistry
Would the following errors cause an increase or decrease in absorbance and % Transmittance? insoluble particles were accidentally pipetted into the cuvette with the solution the cuvette was wet and not prerinsed with the solution. fingerprints were not wiped off the outside of...
May 10, 2007 by jared

Chemistry
Hi was looking to get some help with an experiment. Currently I trying to determine the amount iron in cereal. And was hoping to get some help with one of the questions I have been given. First off I am the recorded absorbance across the region 470 – 490 nm for the 3.00 mg L–1...
October 14, 2014 by Josh

Chemistry DrBob
You told me the steps on a previous post but i must have forgot how to work out absorbance or ICE cus i keep getting the wrong answer ... The standard solution of FeSCN2+ (prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN) has an absorbance of 0.520...
April 10, 2008 by Amy

Chemistry
For solution 1, 4.00mL of 0.0200 M Cr(NO)3 was added to 20.00ml of 0.0200 M Na2H2EDTA, then the a time and absorbance were taken every 5 mins. If at 5:00 min the absorbance was 0.039 how do I find [Cr3+]0, [CrEDTA-]t, and [Cr3+]t. The absorbance at 0:00 mins was 0.039 if it is...
September 17, 2012 by Fred

chemistry
An unknown was prepared with the concentration of 0.000630 M. A Beer's Law plot was prepared using the absorbance values from standard solutions of ASA and a line drawn through all the points passed through the origin with a slope of 1550.2 M–1. The expected absorbance and %T ...
January 27, 2008 by john

chemistry
An unknown was prepared with the concentration of 0.000630 M. A Beer's Law plot was prepared using the absorbance values from standard solutions of ASA and a line drawn through all the points passed through the origin with a slope of 1550.2 M–1. The expected absorbance and %T ...
January 27, 2008 by Michael

Chemistry Help
If a graph is given for a cuvette using a 1.00 cm , predict the graph if a 2.0 cm diameter test tube and a 0.50cm test tube are used. The points for the 1.00cm test tube are (0,0),((2E-5),0.1), ((4E-5),0.2), ((6E-5),0.4), ((8E-5),0.5)...linear graph X=Concentration (molars) Y=...
November 16, 2007 by Zara

chemistry
a solution that has an absorbance of 0.603 is diluted ten fold. What is the absorbance of this solution now?
April 3, 2011 by carla

Chemistry
A metal element (M) forms a hexadentate complex with the ligand ethylenediammine (en). Its formula is M(en)32+. The metal ion and the ligand do not absorb in the visible region of spectrophotometer and a 1.00 cm cuvette, the following absorbances were measured for various ...
August 13, 2012 by John

Biochemistry
Can someone help me calculate protein concentration using the Bradford Assay? If you could show me how to do tube 2, that'd be great. Tube 1: 0 ul Protein Stock Solution, 800 ul Water, 0 ug Protein, Absorbance @595nm = 0 Tube 2: 10 ul Protein Stock Solution, 790 ul Water, 1.4 ...
October 7, 2013 by OR

College Chemistry Lab
The absorbance of a 9.25x10^-8M solution of a fabric dye was measured to be 0.835 at a particular wavelength. What would the absorbance be for a 4.65x10^-8M solution of the same dye under identical conditions?
March 15, 2010 by L**

Chemistry
The standard solution of FeSCN2+ (prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN) has an absorbance of 0.500. If a trial's absorbance is measured to be 0.310 and its initial concentration of SCN– was 0.0010 M, the equilibrium concentration of SCN...
June 29, 2008 by Anonymous

Chemistry
The standard solution of FeSCN2+ (prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN) has an absorbance of 0.550. If a trial's absorbance is measured to be 0.350 and its initial concentration of SCN– was 0.0010 M, the equilibrium concentration of SCN...
June 28, 2008 by Tom

chemistry
The standard solution of FeSCN2+ (prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN) has an absorbance of 0.500. If a trial's absorbance is measured to be 0.310 and its initial concentration of SCN– was 0.0010 M, the equilibrium concentration of SCN...
February 22, 2008 by thuy

chemistry
The standard solution of FeSCN2+ (prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN) has an absorbance of 0.520. If a trial's absorbance is measured to be 0.275 and its initial concentration of SCN– was 0.00060 M, what is the equilibrium ...
April 8, 2008 by Amy

Chemistry
The standard solution of FeSCN2+ (prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN) has an absorbance of 0.530. If a trial's absorbance is measured to be 0.150 and its initial concentration of SCN– was 0.00070 M, the equilibrium concentration of SCN...
April 9, 2008 by Sam

chemistry
The standard solution of FeSCN2+ (prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN) has an absorbance of 0.510. If a trial's absorbance is measured to be 0.250 and its initial concentration of SCN¡V was 0.00050 M, the equilibrium concentration of ...
April 10, 2008 by Gloria

Chemistry
The standard solution of FeSCN2+ (prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN) has an absorbance of 0.500. If a trial's absorbance is measured to be 0.310 and its initial concentration of SCN– was 0.0010 M, the equilibrium concentration of SCN...
August 10, 2008 by Chem help

Chemistry
The standard solution of FeSCN2+ (prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN) has an absorbance of 0.500. If a trial's absorbance is measured to be 0.310 and its initial concentration of SCN– was 0.0010 M, the equilibrium concentration of SCN...
June 20, 2011 by John

chemistry
Solution A, while in a 1.0 cm cell, has an absorbance of 0.390 and a [Cu2+] = 0.0283 M. Then, 6.57 mL of solution A is diluted with pure water to 100.0 mL. What is the absorbance of this diluted solution? I tried but I still don't get it. Can anyone please help! :( Thanks!
April 24, 2010 by hongkong

Chemistry
The standard solution of FeSCN2+ (prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN) has an absorbance of 0.510. If a trial's absorbance is measured to be 0.250 and its initial concentration of SCN– was 0.00050 M, the equilibrium concentration of SCN...
June 28, 2008 by UN

Chemistry
3. What experimental problems would confront you if you attempted to determine the concentration of the metal ions in solutions of each of the following reagents? a. Cr +3 which has a maximum absorbance at 407 nm with absorbtivity of 15 M -1 cm -1 and another at 574 nm with ...
October 14, 2007 by Joe

chem
discuss why it necessary to make absorbance measurements at the wavelength of maximum absorbance
February 6, 2013 by ha

chemistry
The standard solution of FeSCN2+ (prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN) has an absorbance of 0.550. If a trial's absorbance is measured to be 0.350 and its initial concentration of SCN– was 0.0010 M, the equilibrium concentration of SCN...
April 9, 2008 by temperance

General Chemistry.
The absorbance of a chlorophyll a standard solution in ethanol (density = 0.785 g/mL) is measured in a 1.3 cm cuvette or path length. The absorbance is 0.765 and the molar absorptivity coefficient is 86,300 M–1cm–1. The molecular weight for chlorophyll a is 893.49 g/mol. What ...
November 7, 2012 by Shardae.

Chemistry
The standard solution of FeSCN2 (prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN) has an absorbance of 0.550. If a trial's absorbance is measured to be 0.350 and its initial concentration of SCN– was 0.0010 M, the equilibrium concentration of SCN– ...
August 8, 2008 by Blair

chem
A student based the analysis of Cu(II) in a sample on the formation of the blue complex [Cu(H2O)6]+2. A standard solution was made when 1.276g of pure copper wire (MM= 63.546g/mol) was weighed, dissolved in concentrated HNO3, and diluted to 1.00x102mL. The stock solution was ...
November 11, 2013 by Anonymous

chemistry lab
1) If your spectrophotmeter can measure n absorbance up to 1.5, what is the maximum concentration of NADH that you can measure without diluting? 2) If you add 3 mL of water to 1 mL of NADH, mix and get an absorbance of 0.2, what is the concentration of the original NADH ...
February 2, 2008 by jennifer

Chemistry
The rate of a first-order reaction is followed by spectroscopy, monitoring the absorption of a colored reactant at 520 nm . The reaction occurs in a 1.29-cm sample cell, and the only colored species in the reaction has an extinction coefficient of 5700 cm-1M-1 at 520 nm . a) ...
January 26, 2013 by Leslie

Chemistry
The rate of a first-order reaction is followed by spectroscopy, monitoring the absorption of a colored reactant at 520 nm . The reaction occurs in a 1.29-cm sample cell, and the only colored species in the reaction has an extinction coefficient of 5700 cm-1M-1 at 520 nm . a) ...
January 26, 2013 by Leslie

Chemistry
The standard solution of FeSCN2+ (prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN) has an absorbance of 0.530. If a trial's absorbance is measured to be 0.150 and its initial concentration of SCN– was 0.00070 M, the equilibrium concentration of SCN...
April 10, 2008 by Anonymous

Chemistry
Do I solve this by multiplying 1.8645 by 1.14??The equation of your calibration curve from a spectrophotometry experiment was y = 1.8645x. Assuming your calibration curve is set up exactly like it was in lab (concentration in mM on the x axis and absorbance on the y axis), ...
June 25, 2013 by Ann

Chemistry
An unknown was prepared with the concentration of 0.000520 M. A Beer's Law plot was prepared using the absorbance values from standard solutions of ASA and a line drawn through all the points passed through the origin with a slope of 1550.2 M–1. The expected absorbance and %T ...
January 26, 2009 by bon

Chemistry
An unknown was prepared with the concentration of 0.000520 M. A Beer's Law plot was prepared using the absorbance values from standard solutions of ASA and a line drawn through all the points passed through the origin with a slope of 1550.2 M–1 . The expected absorbance and %T...
January 26, 2008 by Maggie Chuang

Chemistry
An unknown was prepared with the concentration of 0.000520 M. A Beer's Law plot was prepared using the absorbance values from standard solutions of ASA and a line drawn through all the points passed through the origin with a slope of 1550.2 M–1. The expected absorbance and %T ...
April 19, 2009 by Joan

college chemistry
An unknown was prepared with the concentration of 0.000266 M. A Beer's Law plot was prepared using the absorbance values from standard solutions of ASA and a line drawn through all the points passed through the origin with a slope of 1646.3 M^–1. What are the expected ...
April 20, 2009 by zahra

Chemistry
An unknown was prepared with the concentration of 0.0000890 M. A Beer's Law plot was prepared using the absorbance values from standard solutions of ASA and a line drawn through all the points passed through the origin with a slope of 1750.0 M–1. The expected absorbance and %T...
January 23, 2010 by Sunny

chemistry
can someone please explain to me in dummy language this question... Why is the graph of transmittance versus concentration not linear?... Thankyou very much
April 2, 2011 by jen

Chemistry DrBob
This is what i posted up a while back... i got to a using 0.520= a (.202M) and got a= 2.57 but now i don't know where to go from there with the ICE The standard solution of FeSCN2+ (prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN) has an absorbance...
April 12, 2008 by Amy

Chemistry
An unknown was prepared with the concentration of 0.000630 M. A Beer's Law plot was prepared using the absorbance values from standard solutions of ASA and a line drawn through all the points passed through the origin with a slope of 1550.2 M–1. The expected absorbance and %T ...
January 24, 2010 by Anonymous

chemistry
An unknown was prepared with the concentration of 0.000630 M. A Beer's Law plot was prepared using the absorbance values from standard solutions of ASA and a line drawn through all the points passed through the origin with a slope of 1550.2 M–1 . The expected absorbance and %T...
April 14, 2011 by ChemLover

Chemistry
It is possible, although less accurate, to do a standard addition with only one sample. An unknown Fe sample was analyzed by AAS and gave an absorbance reading of 0.160. To the same sample we added 1.5ppm Fe and the new absorbance reading was 0.205. Calculate the ppm of the ...
March 5, 2012 by Mae

Chemistry
It is possible, although less accurate, to do a standard addition with only one sample. An unknown Fe sample was analyzed by AAS and gave an absorbance reading of 0.160. To the same sample we added 1.5ppm Fe and the new absorbance reading was 0.205. Calculate the ppm of the ...
March 5, 2012 by Ella

Chemistry
1)Write the general equation used to determine the volume of stock required to make a given concentration of standard? Define any terms you used. ----use the 100ml flasks to create four serial dilutions of the stock 10,000uM nitrate solution that has been provided. Prepare ...
April 23, 2010 by josh

College Chemistry Lab
The absorbance of a 6.3x10^-5M solution of an iron complex was measured to be 0.328 at the optimum wavelength. A second solution of the iron complex has an absorbance of 0.833 measured under identical conditions. What is the molarity of the complex in the SECOND SOLUTION?
March 15, 2010 by L**

Dr. Bob
Okay so the five volumetric flasks came from solutions that the professor told us to get the wavelength for the highest point of absorbance for asked how I got the highest point of absorbance earlier
November 18, 2007 by Suzy

chemistry
The standard solution of FeSCN2+ (prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN) has an absorbance of 0.510. If a trial's absorbance is measured to be 0.250 and its initial concentration of SCN− was 0.00050 M, the equilibrium concentration ...
April 10, 2009 by UCI student

chemistry
The standard solution of FeSCN2+ (prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN) has an absorbance of 0.510. If a trial's absorbance is measured to be 0.250 and its initial concentration of SCN− was 0.00050 M, the equilibrium concentration ...
April 10, 2009 by UCI student

science
college chemistry-absorbance of an equilibrium mixture Problem: A student mixed 4.00mL of 1.02x10^(-1) M Fe(NO3)3 with 100.00mL of 1.98*10^(-4) M KSCN, using 5.0*10^(-1) M HNO3 as the solvent for both solutions, and found the absorbance of the resulting equilibrium mixture to ...
March 14, 2009 by Mary

chem
The standard solution of FeSCN2+ (prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN) has an absorbance of 0.520. If a trial's absorbance is measured to be 0.275 and its initial concentration of SCN– was 0.00060 M, what is the equilibrium ...
April 10, 2008 by anonymous

Science
The standard solution of FeSCN2+ (prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN) has an absorbance of 0.550. If a trial's absorbance is measured to be 0.350 and its initial concentration of SCN– was 0.0010 M, the equilibrium concentration of SCN...
November 3, 2008 by Bobby

chem
The standard solution of FeSCN2+ (prepared by combining 9.00 mL of 0.200 M Fe(NO3)3 w/1.00 mL of 0.0020 M KSCN) has an absorbance of 0.520. If a trial's absorbance is measured to be 0.275 and its initial concentration of SCN– was 0.00060 M, the equilibrium concentration of SCN...
April 11, 2010 by Adam

Chemistry
The absorbance of a chlorophyll a standard solution in ethanol (density = 0.785 g/mL) is measured in a 1.3 cm cuvette or path length. The absorbance is 0.435 and the molar absorptivity coefficient is 86,300 M–1cm–1. The molecular weight for chlorophyll a is 893.49 g/mol. The ...
July 16, 2012 by Anonymous

Chemistry
The absorbance of a chlorophyll a standard solution in ethanol (density = 0.785 g/mL) is measured in a 1.3 cm cuvette or path length. The absorbance is 0.435 and the molar absorptivity coefficient is 86,300 M–1cm–1. The molecular weight for chlorophyll a is 893.49 g/mol. The ...
July 16, 2012 by Anonymous

chem
the % T of brass solution is 55.0%, 1)what is the Transmittance(T)?
July 11, 2011 by a

chemistry
At l=530 nm:aCuSO4=7.544L/mol-cm aKMnO4= 3.645 L/mol-cm At l=800nm: aCuSO4=2.908L/mol-cm aKMnO4= 5.412L/mol-cm you use a celleith a path length of 1.0cm An unknown solution containing both CuSO4 and KMnO4 gave an absorbance reading of 0.679 at 530nm and an absorbance of 0.525 ...
November 7, 2010 by Macy

DRBOB
okay you talked about using a graph and we made one so this is the formula from it. y = 2.2019x y = absorbance x= concentration so if i have an absorbance of .02, do i do... .02/2.2019= .0091 .0091 would be x so it would be the concentration is this right???
March 11, 2009 by jaseline

chemistry
How are absorbance and transmission spectra related?
September 7, 2010 by Anonymous

chemistry
What is the % transmittance for each of these errors Washing a cuvette with DI water, then failing to rinse it with the solution to be measured Failing to wipe off fingerprints from the cuvette. Changing the wavelength from maxtomax+10 nm.
January 26, 2009 by leah

Chem
Determine the concentration of a dioxin solution whose percent absorbance is 0.40% This is the resulting: Absorbance Dioxin 0.64 5.5 0.76 6.3 1.0 8.0 But why can't I figure out the concentration whose percentage is .40%?
March 31, 2010 by Stacey

chemistry, biotechnology
The question is: "The molar extinction coefficient of pure antibody is 1.4 absorbance units per milligram antibody @280nm. You have a concentrated antibody solution, so you make a 5-fold dilution and measure @280, getting an absorbance of 0.845. What is the concentration of ...
October 2, 2014 by Jennifer

chemistry
What is the concentration of a solution if the absorbance is 0.66 and the constant (a x b) is 8.2 L/mol?
October 1, 2008 by aaloy

Chemistry
Cu(NH3)2^+ is a colourless compound. Will there be any absorbance at 600nm?
March 16, 2010 by Alan

chemistry
Fish-liver oil is a good source of Vitamin A. When 0.1232 g of fish liver oil is dissolved in 500. mL of solvent, an absorbance of 0.724 is recorded. When 0.00167 g of Vitamin A is dissolved in 250. mL of solvent, an absorbance of 1.018 is recorded. Calculate the mass percent ...
February 6, 2011 by dave

chemistry
Fish-liver oil is a good source of Vitamin A. When 0.1232 g of fish liver oil is dissolved in 500. mL of solvent, an absorbance of 0.724 is recorded. When 0.00167 g of Vitamin A is dissolved in 250. mL of solvent, an absorbance of 1.018 is recorded. Calculate the mass percent ...
February 8, 2011 by David

biology
does dark reaction helps in transmittance and conservation of energy
June 26, 2014 by AYESHA

Chemistry
why do we use different instrument to make absorbance and fluorescence measurments?
December 8, 2008 by Beckhamano

Chemistry
Determine the concentration of a dioxin solution whose percent absorbance is 0.40%
March 31, 2010 by Stacey

science chemistry
what is the purpose of using deinonized water to adjust the Spec 20 to 0 absorbance?
September 11, 2011 by sibi

Chemistry - Kc question
What would happen to Kc values in an experiment if the Beer's law constance (k) value used was low ( e.g you used 4000/M when the actual constant had a value of 5000/M)? Explain your answer Absorbance = k*length cell*concentration Cell length is constant. You read an ...
August 5, 2007 by matt

Analytical Chemistry
How many mg of X is contained in 25 ml of a solution giving an absorbance of 0.250 at 400 nm when measured with a 1 cm cell ?
November 30, 2012 by AREEJ

Analytical Chemistry
How many mg of X is contained in 25 ml of a solution giving an absorbance of 0.250 at 400 nm when measured with a 1 cm cell ?
November 30, 2012 by AREEJ

chemistry
for our lab, we are given the molarity of ClO-. We are then supposed to use beer's law to determine the molarity of the dye that was used to make the solution with. For the dye, use the first absorbance value, Ao, and calculate the initial concentration of the dye using Beer’s...
February 21, 2011 by Anonymouse one

chemistry
1. A sample weighing 1.30 mg was analyzed to determine the concentration of a certain compound (FW =292.16 g/mol) using UV/Visible spectrometry. First, the sample was dissolved in 5.00 mL volumetric flask. A 1.00 mL aliquot was drawn up, placed in a 10.0 mL volumetric flask ...
October 2, 2014 by Chris

chem
An unknown was prepared with the concentration of 0.000630 M. A Beer's Law plot was prepared using the absorbance values from standard solutions of ASA and a line drawn through all the points passed through the origin with a slope of 1550.2 M–1. The expected absorbance and %T ...
April 20, 2009 by eve

chem
An unknown was prepared with the concentration of 0.000630 M. A Beer's Law plot was prepared using the absorbance values from standard solutions of ASA and a line drawn through all the points passed through the origin with a slope of 1550.2 M–1 . The expected absorbance and %T...
April 19, 2009 by eve

Honors Chemistry
Help! I do not understand this question. What do you think the effect of concentration might be on the perceived level of a molecules absorbance?
November 1, 2009 by Ashley

chemistry
Substance X has a molar extinction coefficient (E) of 4725 l.mol-1 cm-1. How many micromoles of X are needed to produce an absorbance of 1.0 in a 1 ml cuvette?
April 29, 2012 by tulasi

chemistry
Expressing concentration in units of μg/mL or mg/mL are common in biochemistry, where accurate molecular weights of biomolecules are not always known. The plot below is the standard curve of a Bradford assay, a colorimetric method used to determine the concentration of ...
September 17, 2013 by Libbie

Chem
I got one more question. I tried to figure out what should it be. But still I don't have idea yet... Help me please.... The question is The expected absorbance range for the solutions to be tested is between 0.01 and 0.1. Describe what Simon will need to do to have confidence ...
October 12, 2010 by Kim

Chemistry (URGENT)
In order to analyze the waste water containing Co^2+ from a manufacturing process, 1.0L of water was evaporated to 10.0mL, then placed in a spectrophotometer tube. The absorbance was found to be 0.20. Using your calibration curve, calculate the number of milligrams of co^2+ in...
December 16, 2010 by John

can please somebody tell how to solve this problem
An unknown was prepared with the concentration of 0.000520 M. A Beer's Law plot was prepared using the absorbance values from standard solutions of ASA and a line drawn through all the points passed through the origin with a slope of 1550.2 M–1. The expected absorbance and %T ...
October 2, 2012 by anchal

chemistry
If the maximum sensitivity of absorbance is at 450nm would the same value of K be obtain at 400nm or 500nm? Please explain.
October 18, 2011 by mary

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