Wednesday
April 16, 2014

Search: chemistry- absorbance & transmittance

Number of results: 101,132

Chemistry
I answered this just a few posts back but the molarity was different. Absorbance = slope x C will get A. Then A = log (1/T) will get transmittance. transmittance x 100 = %T.
Saturday, January 26, 2008 at 11:15pm by drbob222

chemistry
1. decrease absorbance and decrease % transmittance 2. decrease absorbance and increase % transmittance 3. increase absorbance and decrease % transmittance 4. decrease absorbance and increase % transmittance
Thursday, May 10, 2007 at 10:04pm by Allison

chemistry (correction)
Ignore my previous answer. I was using the transmittance equation instead of absorbance. I should have known better. Absorbance = 1 - e^-kX If absorbance = 0.50, kX = 0.6931 If absorbance = 0.31, e^-kX = 0.69 and kX = 0.3711 X is the path length which stays the same, so k ...
Friday, February 22, 2008 at 11:53am by drwls

chemistry
Absorbance = log (1/transmittance)
Tuesday, September 7, 2010 at 12:30pm by DrBob222

chemistry
By the way, you MAY subract absorbance from absorbance. Some preprinted graph papers as well as some spectrophotometers are calibrated in percent transmittance and you may NOT subtract percent T values. They must first be converted to A valures through log 1/T, then may be ...
Friday, September 14, 2007 at 7:33am by DrBob222

chemistry
Absorbance = slope*molarity will get A for you. Then A = log (1/T) for transmittance. T*100 = %T.
Saturday, January 26, 2008 at 3:26pm by DrBob222

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 ...
Friday, February 16, 2007 at 1:00pm by christine

chemistry
In dummy language, it is not linear because it is logarithmic by definition. absorbance=constant*concentration=kc which is linear with concentration. but absorbance=10*log P/Po= =10log 1/Transmittance because transmittance=P/Po which leads to T=e-k*concentration Thus, it is ...
Saturday, April 2, 2011 at 5:12pm by bobpursley

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...
Tuesday, February 22, 2011 at 4:19pm by Unknown

chemistry
1.) Increase absorbance & decrease % transmittance all the other answer above are correct
Thursday, May 10, 2007 at 10:04pm by Randi

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?
Monday, January 31, 2011 at 6:27pm 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?
Friday, September 14, 2007 at 7:33am by smiley

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 ...
Wednesday, February 26, 2014 at 3:17pm 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 ...
Wednesday, February 26, 2014 at 2:39pm by Dan

chemistry
What Dr. Bob222 did was give you the setups to calculate the molarity. Transmittance is related to absorbance, so you have to calculate the absorbance of the blank and subtract it from your sample to to acquire the correct absorbance value for your sample. A unknown- A blank= ...
Sunday, July 28, 2013 at 7:33pm by Devron

chemistry
how do I plot absorbance vs concentration and transmittance %T vs concentration on the same graph??
Saturday, November 6, 2010 at 12:48pm by Vivian

science chemistry
You need a reference solution. Frankly, deionized water is usually not specified in this teaching machine, rather distilled water. If you wish to learn something, let it warm up 5 min, calibrate it with deionized water, set the absorbance and transmittance, then put a sample ...
Sunday, September 11, 2011 at 3:17pm by bobpursley

Chemistry
a. Transmittance = I/Io b. the least reflective c. the least absorbance d. the most reflective.
Sunday, September 18, 2011 at 3:41am by DrBob222

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...
Monday, May 14, 2007 at 3:08am 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 ...
Monday, October 16, 2006 at 7:10pm by Anonymous

chemistry
You missed my first pick-up line. I don't know how the "trial runs" were treated. I assume you mean by "trial's absorbance" the absorbance of the unknown sample. How was the sample treated before the absorbance was measured?
Friday, April 10, 2009 at 3:10am by DrBob222

Chem
1. You are close to being right if not exactly correct. You want to measure the transmittance of the sample (which happens to be dissolved in water). So you set the solvent at 100% transmittance so that the reading with the sample will be that due to the material being ...
Tuesday, February 22, 2011 at 4:19pm by DrBob222

Chemistry
Help! If I have 0.0031 absorbance/sec, how would I convert this to absorbance/minute? Thanks
Tuesday, October 22, 2013 at 1:06am by Anon

Chemistry
1. The absorbance values of the five known solutions. 2. A graph plotting A vs C. 3. The absorbance of the unknown.
Monday, March 4, 2013 at 4:05pm by DrBob222

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.
Wednesday, March 7, 2012 at 1:50pm by Lora

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 ...
Saturday, April 20, 2013 at 2:11am 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 % ...
Wednesday, December 1, 2010 at 4:53pm by jes

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...
Tuesday, March 16, 2010 at 7:29pm 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 0.510. 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...
Wednesday, April 9, 2008 at 9:42pm by Jason

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 ...
Sunday, January 27, 2008 at 4:04pm 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 ...
Sunday, January 27, 2008 at 4:22pm by Michael

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?
Thursday, February 23, 2012 at 2:40pm by ella

chemistry
a solution that has an absorbance of 0.603 is diluted ten fold. What is the absorbance of this solution now?
Sunday, April 3, 2011 at 6:55pm by carla

Chemistry
I assume y is Absorbance and x is concn. So plug 0.254 in for y (absorbance) and solve for x. I never did this in school. We plotted the data and read the concn from the graph. You could do that, too.
Sunday, April 5, 2009 at 5:19pm by DrBob222

chemistry
The answer is "yes" but I am not sure what formula you are referring to. Are you expected to use the absorbance v. time graph to get the half-life? If so, •Select a point on the graph with a high value for absorbance, A. Read the time in minutes, T1. •On the absorbance axis, ...
Monday, May 17, 2010 at 9:14pm by GK

Chemistry
It tells you that the enzyme is all used up. And what do you mean about the absorbance being FASTER. Absorbance can be more or it can be less but it CAN'T be faster or slower.
Monday, October 29, 2012 at 1:47am by DrBob222

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...
Thursday, May 10, 2007 at 10:04pm by jared

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...
Monday, September 17, 2012 at 3:22pm by Fred

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...
Monday, April 14, 2008 at 1:56pm by david

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...
Thursday, April 10, 2008 at 2:02pm by Amy

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=...
Friday, November 16, 2007 at 1:38pm by Zara

chemistry
1. Because it's a log relationship. A = log 1/T 2. I don't know unless it's to see where the material absorbs most and least and which absorbance peak should be used. 3. Don't you need to know where the absorbance starts (how much) as well as where it ends (how much).?
Friday, September 14, 2007 at 7:33am by DrBob222

chemistry
You use the absorbance and a known concn or the constant value. A = abc where A is absorbance, a is a constant, b is the path length, and c is the concn Iif c is in moles/L, then a is called the molar absorptivity constant).
Wednesday, March 11, 2009 at 11:43am by DrBob222

chemistry
aparently it is the 100% transmittance one....
Saturday, April 17, 2010 at 7:31pm by me

chem
discuss why it necessary to make absorbance measurements at the wavelength of maximum absorbance
Wednesday, February 6, 2013 at 9:21pm by ha

College Chemistry Lab
Absorbance = kC Plug in A and C from the first run and calculate k. Use k and absorbance of second run to calculate C for second sample.
Monday, March 15, 2010 at 11:54pm by DrBob222

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?
Monday, March 15, 2010 at 11:56pm by L**

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!
Saturday, April 24, 2010 at 10:02am by hongkong

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 ...
Monday, October 7, 2013 at 5:29pm by OR

chem
The Beer's law plot is usually absorbance (y axis) against concentration (x axis) so the slope is absorbance (no units)/concentration (mol litre-1) so the units of the slope are litre mole-1 Thus to find the absorbance of an unknown we need to multiply the concentration of the...
Monday, April 20, 2009 at 4:09am by Dr Russ

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 ...
Wednesday, November 7, 2012 at 3:21am by Shardae.

science chemistry
Read Bob Pursley's answer again. I assume zero means zero absorbance units. 100% T is the same.You need a reference. What do you think would happen if you turn on the machine, someone twists the knob, and the machine reads 50%T? Now you measure your sample. Will the absorbance...
Sunday, September 11, 2011 at 3:17pm by DrBob222

chemistry
Solution A initial: Absorbance = kc Substitute A and c, calculate k. Diluted solution: new concn = 0.0283 x (6.57/100) Substitute k and new c, calculate Absorbance.
Saturday, April 24, 2010 at 10:02am by DrBob222

chemistry
the numbers vary a lot. like some of the numbers are .004 and some are 1999. how would you graph that big of a difference?? and it asks questions like at what wavelength was the absorbance the greatest but for the color red i recorded the absorbance to be 1999 at 6 different ...
Tuesday, November 6, 2007 at 4:50pm by S

Chemistry
When a blank is used the spectrophotometer is made to read 100% with the blank inserted (you may make it read A = 0 which is the same as 100%T). So if you set the unit to read 100%T (0 Absorbance) with the blank, what will it read if you next insert a dilute Cr solution. We ...
Tuesday, February 25, 2014 at 12:08am by DrBob222

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...
Sunday, June 29, 2008 at 2:03am 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...
Saturday, June 28, 2008 at 12:34am 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...
Friday, February 22, 2008 at 11:53am 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 ...
Tuesday, April 8, 2008 at 9:34pm 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...
Wednesday, April 9, 2008 at 12:06am 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 ...
Thursday, April 10, 2008 at 3:26am 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...
Sunday, August 10, 2008 at 6:36pm 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...
Monday, June 20, 2011 at 11:08pm by John

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 ...
Monday, January 26, 2009 at 3:08pm by bon

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 ...
Saturday, February 2, 2008 at 4:03pm by jennifer

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...
Saturday, June 28, 2008 at 4:59pm by UN

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), ...
Tuesday, June 25, 2013 at 2:16pm by Ann

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...
Saturday, January 26, 2008 at 3:26pm by Anonymous

Chem
Then, What should be the unit for 9.625? I thought that is the absorbance. So I used nm unit which is for absorbance.
Monday, October 11, 2010 at 10:59pm by Kim

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...
Wednesday, April 9, 2008 at 5:30pm by temperance

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...
Saturday, January 26, 2008 at 11:15pm 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 ...
Sunday, April 19, 2009 at 2:34am 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 ...
Monday, April 20, 2009 at 12:24am 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...
Saturday, January 23, 2010 at 3:49pm by Sunny

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– ...
Friday, August 8, 2008 at 6:48pm by Blair

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...
Saturday, January 26, 2008 at 3:26pm by eve

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 ...
Sunday, January 24, 2010 at 6:57pm 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...
Thursday, April 14, 2011 at 5:54pm by ChemLover

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 ...
Monday, November 11, 2013 at 10:10pm by Anonymous

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) ...
Saturday, January 26, 2013 at 9:21pm 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) ...
Saturday, January 26, 2013 at 9:21pm by Leslie

Chemistry
The answer is definitely "The blank for this experiment must have 100 % transmittance if placed in a spectrometer (Spec 20)."
Sunday, April 26, 2009 at 4:22am by Rohan

Chemistry
I agree with 1. The standard curve is too high so readings from it will be too high. 2. It depends upon where the beam is. If the liquid in the cuvette is enough to encounter all of the light beam there will be no effect. If the beam is higher than the top of the liquid, there...
Sunday, February 23, 2014 at 3:39am by DrBob222

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?
Monday, March 15, 2010 at 11:54pm by L**

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 ...
Sunday, October 14, 2007 at 9:21am by Joe

Chemistry
YEA!!!!!!!! I GOT IT RIGHT ANSWER IS The blank for this experiment must have 100 % transmittance if placed in a spectrometer (Spec 20).
Sunday, April 26, 2009 at 4:22am by UCIANTEATER

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
Saturday, April 2, 2011 at 5:12pm by jen

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...
Thursday, April 10, 2008 at 12:42am by Anonymous

chemistry
You don't give much information for a detailed analysis; however, when a sample is scanned, typiclly the spectrophotomter is set at say 400 nm, the scan is turned on and the instrument measures the absorbance and a pen marks the absorbance on the paper (usually a preprinted ...
Friday, September 14, 2007 at 7:33am by DrBob222

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 ...
Friday, April 23, 2010 at 3:12pm by josh

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
Sunday, November 18, 2007 at 9:49pm by Suzy

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 ...
Monday, March 5, 2012 at 4:05am 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 ...
Monday, March 5, 2012 at 3:23pm by Ella

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 ...
Monday, August 13, 2012 at 12:30am by John

chem
I worked this about an two hours ago. Perhaps for another student. Normally, the concn curves for spectrophotometric work is done by plotting A (absorbance) on the Y axis and c (concn) on the x axis. Since you have a straight line, the equation for a straight line is y = mx + ...
Sunday, April 19, 2009 at 10:30pm by DrBob222

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...
Saturday, April 12, 2008 at 8:14pm by Amy

chem lab
I suspect that the absorbance would increase. The fingerprint would cause the light going through the cuvette to be distorted somewhat. This would lead to less light hitting the detector and thus, a higher absorbance.
Thursday, November 13, 2008 at 5:23pm by ~christina~

Chem
I am unfamiliar with an absorbance of 0.40%. 0.40, yes, but not the percent. If it really is 0.4%, then I would use 0.004 for A. A = kc where A = absorbance, c is concn and k is a constant. You must calculate the k. Use any one of the data points, for example, the first one, ...
Wednesday, March 31, 2010 at 1:52pm by DrBob222

chemistry
i have %composition and absorbance.
Tuesday, November 6, 2007 at 4:50pm by S

Chemistry
Absorbance std = k*concn std 2.55 = k*8 Solve for k. Absorbance sample = k*concn sample 2.31 = k from above*concn sample Solve for c sample.
Wednesday, March 7, 2012 at 1:50pm by DrBob222

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