Hesabu ujazo kwa kutumia Sheria ya Beer-Lambert kwa kuingiza urefu wa njia, ufanisi wa molar, na mkusanyiko. Muhimu kwa spectroscopy, kemia ya uchambuzi, na matumizi ya maabara.
A = Δ à c à l
Ambapo A ni upokeaji, Δ ni ufanisi wa molar, c ni mkusanyiko, na l ni urefu wa njia.
Hii inaonyesha asilimia ya mwanga inayopokelewa na suluhisho.
Beer-Lambert Law Calculator ni chombo chenye nguvu kilichoundwa kuhesabu unyonyaji wa suluhisho kulingana na kanuni za msingi za unyonyaji wa mwanga katika spectroscopy. Sheria hii, inayojulikana pia kama Sheria ya Beer au Sheria ya Beer-Lambert-Bouguer, ni kanuni muhimu katika kemia ya uchambuzi, biokemia, na spectroscopy inayohusisha kupungua kwa mwanga na mali za nyenzo ambayo mwanga unapitishwa. Kihesabu chetu kinatoa njia rahisi na sahihi ya kubaini thamani za unyonyaji kwa kuingiza vigezo vitatu muhimu: urefu wa njia, uwezo wa unyonyaji wa molar, na mkusanyiko.
Iwe wewe ni mwanafunzi anayejifunza misingi ya spectroscopy, mtafiti anayechambua vipengele vya kemikali, au mtaalamu katika sekta ya dawa, kihesabu hiki kinatoa suluhisho rahisi kwa hesabu zako za unyonyaji. Kwa kuelewa na kutumia Sheria ya Beer-Lambert, unaweza kubaini kwa kiasi mkusanyiko wa viumbe vinavyonyonya katika suluhisho, mbinu muhimu katika kemia ya kisasa ya uchambuzi.
Sheria ya Beer-Lambert inawakilishwa kimaandishi kama:
Ambapo:
Unyonyaji ni kipimo kisichokuwa na kipimo, mara nyingi kinachoonyeshwa katika "vitengo vya unyonyaji" (AU). Kinawakilisha logarithm ya uwiano wa nguvu ya mwanga wa kuingia hadi mwanga wa kupita:
Ambapo:
Uhusiano kati ya uhamasishaji (T) na unyonyaji (A) unaweza pia kuonyeshwa kama:
Asilimia ya mwanga unaonyonywa na suluhisho inaweza kuhesabiwa kama:
Sheria ya Beer-Lambert inatumika chini ya hali fulani:
Katika mkusanyiko wa juu, kutofautiana na sheria kunaweza kutokea kwa sababu ya:
Kihesabu chetu cha Sheria ya Beer-Lambert kimeundwa kwa urahisi na usahihi akilini. Fuata hatua hizi ili kuhesabu unyonyaji wa suluhisho lako:
Ingiza Urefu wa Njia (l): Ingiza umbali ambao mwanga hupita kupitia nyenzo, kawaida upana wa cuvette au chombo cha sampuli, kupimwa kwa sentimita (cm).
Ingiza Uwezo wa Unyonyaji (Δ): Ingiza koefisienti ya unyonyaji wa molar ya dutu, ambayo ni kipimo cha jinsi dutu inavyonyonya mwanga kwa wigo maalum, kupimwa kwa L/(mol·cm).
Ingiza Mkusanyiko (c): Ingiza mkusanyiko wa viumbe vinavyonyonya katika suluhisho, kupimwa kwa moles kwa lita (mol/L).
Tazama Matokeo: Kihesabu kitaweza moja kwa moja kuhesabu thamani ya unyonyaji kwa kutumia sawa ya Beer-Lambert (A = Δ à c à l).
Uonyeshaji: Tazama uwakilishi wa picha unaoonyesha asilimia ya mwanga unaonyonywa na suluhisho lako.
Kihesabu kinafanya uhalali wa aina zifuatazo kwenye ingizo lako:
Ikiwa utaingiza data isiyo sahihi, ujumbe wa kosa utaonekana, ukikuelekeza kurekebisha ingizo kabla ya kuendelea na hesabu.
Thamani ya unyonyaji inakueleza jinsi mwanga unavyonyonywa na suluhisho lako:
Uwakilishi wa picha unakusaidia kuelewa kiwango cha unyonyaji wa mwanga kwa njia ya kiufundi, ukionyesha asilimia ya mwanga wa kuingia inayonyonywa kadri inavyopita kupitia sampuli yako.
Sheria ya Beer-Lambert inatumika katika nyanja nyingi za kisayansi na viwandani:
Mtaalamu wa biokemia anataka kubaini mkusanyiko wa suluhisho la protini kwa kutumia spectrophotometer:
Kwa kutumia Sheria ya Beer-Lambert: c = A / (Δ à l) = 0.75 / (5,000 à 1) = 0.00015 mol/L = 0.15 mM
Mkemia anajiandaa suluhisho la permanganate ya potasiamu (KMnOâ) na anataka kuthibitisha mkusanyiko wake:
Unyonyaji unaotarajiwa: A = Δ à c à l = 2,420 à 0.002 à 2 = 9.68
Ikiwa unyonyaji wa kupimwa unapingana kwa kiasi kikubwa na thamani hii, mkusanyiko wa suluhisho unaweza kuhitaji marekebisho.
Ingawa Sheria ya Beer-Lambert inatumika sana, kuna hali ambapo mbinu mbadala zinaweza kuwa bora zaidi:
Sheria ya Beer-Lambert inachanganya kanuni zilizogunduliwa na wanasayansi wawili wakifanya kazi kwa uhuru:
Kuunganisha kanuni hizi kumerevuka kemia ya uchambuzi kwa kutoa njia ya kimaadili ya kubaini mkusanyiko kwa kutumia unyonyaji wa mwanga. Leo, Sheria ya Beer-Lambert inabaki kuwa kanuni muhimu katika spectroscopy na inaunda msingi wa mbinu nyingi za uchambuzi zinazotumika katika nyanja za kisayansi.
Hapa kuna mifano ya msimbo inayoonyesha jinsi ya kutekeleza Sheria ya Beer-Lambert katika lugha mbalimbali za programu:
1' Excel formula to calculate absorbance
2=PathLength*MolarAbsorptivity*Concentration
3
4' Excel VBA function for Beer-Lambert Law
5Function CalculateAbsorbance(PathLength As Double, MolarAbsorptivity As Double, Concentration As Double) As Double
6 CalculateAbsorbance = PathLength * MolarAbsorptivity * Concentration
7End Function
8
9' Calculate transmittance from absorbance
10Function CalculateTransmittance(Absorbance As Double) As Double
11 CalculateTransmittance = 10 ^ (-Absorbance)
12End Function
13
14' Calculate percent absorbed
15Function CalculatePercentAbsorbed(Transmittance As Double) As Double
16 CalculatePercentAbsorbed = (1 - Transmittance) * 100
17End Function
18
1import numpy as np
2import matplotlib.pyplot as plt
3
4def calculate_absorbance(path_length, molar_absorptivity, concentration):
5 """
6 Calculate absorbance using the Beer-Lambert Law
7
8 Parameters:
9 path_length (float): Path length in cm
10 molar_absorptivity (float): Molar absorptivity in L/(mol·cm)
11 concentration (float): Concentration in mol/L
12
13 Returns:
14 float: Absorbance value
15 """
16 return path_length * molar_absorptivity * concentration
17
18def calculate_transmittance(absorbance):
19 """Convert absorbance to transmittance"""
20 return 10 ** (-absorbance)
21
22def calculate_percent_absorbed(transmittance):
23 """Calculate percentage of light absorbed"""
24 return (1 - transmittance) * 100
25
26# Example usage
27path_length = 1.0 # cm
28molar_absorptivity = 1000 # L/(mol·cm)
29concentration = 0.001 # mol/L
30
31absorbance = calculate_absorbance(path_length, molar_absorptivity, concentration)
32transmittance = calculate_transmittance(absorbance)
33percent_absorbed = calculate_percent_absorbed(transmittance)
34
35print(f"Absorbance: {absorbance:.4f}")
36print(f"Transmittance: {transmittance:.4f}")
37print(f"Percent Absorbed: {percent_absorbed:.2f}%")
38
39# Plot absorbance vs. concentration
40concentrations = np.linspace(0, 0.002, 100)
41absorbances = [calculate_absorbance(path_length, molar_absorptivity, c) for c in concentrations]
42
43plt.figure(figsize=(10, 6))
44plt.plot(concentrations, absorbances)
45plt.xlabel('Concentration (mol/L)')
46plt.ylabel('Absorbance')
47plt.title('Beer-Lambert Law: Absorbance vs. Concentration')
48plt.grid(True)
49plt.show()
50
1/**
2 * Calculate absorbance using the Beer-Lambert Law
3 * @param {number} pathLength - Path length in cm
4 * @param {number} molarAbsorptivity - Molar absorptivity in L/(mol·cm)
5 * @param {number} concentration - Concentration in mol/L
6 * @returns {number} Absorbance value
7 */
8function calculateAbsorbance(pathLength, molarAbsorptivity, concentration) {
9 return pathLength * molarAbsorptivity * concentration;
10}
11
12/**
13 * Calculate transmittance from absorbance
14 * @param {number} absorbance - Absorbance value
15 * @returns {number} Transmittance value (between 0 and 1)
16 */
17function calculateTransmittance(absorbance) {
18 return Math.pow(10, -absorbance);
19}
20
21/**
22 * Calculate percentage of light absorbed
23 * @param {number} transmittance - Transmittance value (between 0 and 1)
24 * @returns {number} Percentage of light absorbed (0-100)
25 */
26function calculatePercentAbsorbed(transmittance) {
27 return (1 - transmittance) * 100;
28}
29
30// Example usage
31const pathLength = 1.0; // cm
32const molarAbsorptivity = 1000; // L/(mol·cm)
33const concentration = 0.001; // mol/L
34
35const absorbance = calculateAbsorbance(pathLength, molarAbsorptivity, concentration);
36const transmittance = calculateTransmittance(absorbance);
37const percentAbsorbed = calculatePercentAbsorbed(transmittance);
38
39console.log(`Absorbance: ${absorbance.toFixed(4)}`);
40console.log(`Transmittance: ${transmittance.toFixed(4)}`);
41console.log(`Percent Absorbed: ${percentAbsorbed.toFixed(2)}%`);
42
1public class BeerLambertLaw {
2 /**
3 * Calculate absorbance using the Beer-Lambert Law
4 *
5 * @param pathLength Path length in cm
6 * @param molarAbsorptivity Molar absorptivity in L/(mol·cm)
7 * @param concentration Concentration in mol/L
8 * @return Absorbance value
9 */
10 public static double calculateAbsorbance(double pathLength, double molarAbsorptivity, double concentration) {
11 return pathLength * molarAbsorptivity * concentration;
12 }
13
14 /**
15 * Calculate transmittance from absorbance
16 *
17 * @param absorbance Absorbance value
18 * @return Transmittance value (between 0 and 1)
19 */
20 public static double calculateTransmittance(double absorbance) {
21 return Math.pow(10, -absorbance);
22 }
23
24 /**
25 * Calculate percentage of light absorbed
26 *
27 * @param transmittance Transmittance value (between 0 and 1)
28 * @return Percentage of light absorbed (0-100)
29 */
30 public static double calculatePercentAbsorbed(double transmittance) {
31 return (1 - transmittance) * 100;
32 }
33
34 public static void main(String[] args) {
35 double pathLength = 1.0; // cm
36 double molarAbsorptivity = 1000; // L/(mol·cm)
37 double concentration = 0.001; // mol/L
38
39 double absorbance = calculateAbsorbance(pathLength, molarAbsorptivity, concentration);
40 double transmittance = calculateTransmittance(absorbance);
41 double percentAbsorbed = calculatePercentAbsorbed(transmittance);
42
43 System.out.printf("Absorbance: %.4f%n", absorbance);
44 System.out.printf("Transmittance: %.4f%n", transmittance);
45 System.out.printf("Percent Absorbed: %.2f%%%n", percentAbsorbed);
46 }
47}
48
Sheria ya Beer-Lambert ni uhusiano katika optics unaohusisha kupungua kwa mwanga na mali za nyenzo ambayo mwanga unapitishwa. Inasema kuwa unyonyaji unahusiana moja kwa moja na mkusanyiko wa viumbe vinavyonyonya na urefu wa njia ya sampuli.
Sheria ya Beer-Lambert inaweza kutokuwepo chini ya hali fulani:
Uwezo wa unyonyaji wa molar unagunduliwa kwa majaribio kwa kupima unyonyaji wa suluhisho zenye mkusanyiko na urefu wa njia uliojulikana, kisha kutatua sawa ya Beer-Lambert. Ni maalum kwa kila dutu na hubadilika na mawimbi, joto, na solvent.
Ndio, kwa mchanganyiko ambapo vipengele havishughuliki, unyonyaji wa jumla ni jumla ya unyonyaji wa kila kipengele. Hii inawakilishwa kama: A = (Δâcâ + Δâcâ + ... + Δâcâ) Ă l ambapo Δâ, Δâ, nk. ni uwezo wa unyonyaji wa kila kipengele, na câ, câ, nk. ni mkusanyiko wao.
Unyonyaji na wiani wa macho ni kipimo sawa. Wote wawili wanarejelea logarithm ya uwiano wa nguvu ya mwanga wa kuingia hadi mwanga wa kupita. Neno "wiani wa macho" mara nyingi linapendelea katika maombi ya kibaiolojia, wakati "unyonyaji" unatumika zaidi katika kemia.
Kihesabu kinatoa matokeo yenye usahihi wa juu wa nambari, lakini usahihi wa matokeo unategemea usahihi wa thamani zako za ingizo. Kwa matokeo sahihi zaidi, hakikisha kwamba:
Ingawa Sheria ya Beer-Lambert iligunduliwa kwa suluhisho za kioevu, inaweza kutumika kwa gesi na, kwa marekebisho, kwa sampuli zingine za imara. Kwa sampuli za imara zenye kutawanya mwanga kwa kiasi kikubwa, mifano mbadala kama vile nadharia ya Kubelka-Munk inaweza kuwa bora zaidi.
Joto linaweza kuathiri vipimo vya unyonyaji kwa njia kadhaa:
Unapaswa kawaida kutumia mawimbi ambapo viumbe vinavyonyonya vina unyonyaji mkubwa na wa tabia. Mara nyingi, hii ni katika au karibu na kilele cha unyonyaji katika spektra. Kwa kazi za kiasi, ni bora kuchagua mawimbi ambapo mabadiliko madogo ya mawimbi hayawezi kusababisha mabadiliko makubwa katika unyonyaji.
Beer, A. (1852). "Bestimmung der Absorption des rothen Lichts in farbigen FlĂŒssigkeiten" [Determination of the absorption of red light in colored liquids]. Annalen der Physik und Chemie, 86: 78â88.
Ingle, J. D., & Crouch, S. R. (1988). Spectrochemical Analysis. Prentice Hall.
Perkampus, H. H. (1992). UV-VIS Spectroscopy and Its Applications. Springer-Verlag.
Harris, D. C. (2015). Quantitative Chemical Analysis (9th ed.). W. H. Freeman and Company.
Skoog, D. A., Holler, F. J., & Crouch, S. R. (2017). Principles of Instrumental Analysis (7th ed.). Cengage Learning.
Parson, W. W. (2007). Modern Optical Spectroscopy. Springer-Verlag.
Lakowicz, J. R. (2006). Principles of Fluorescence Spectroscopy (3rd ed.). Springer.
Ninfa, A. J., Ballou, D. P., & Benore, M. (2010). Fundamental Laboratory Approaches for Biochemistry and Biotechnology (2nd ed.). Wiley.
Swinehart, D. F. (1962). "The Beer-Lambert Law". Journal of Chemical Education, 39(7): 333-335.
Mayerhöfer, T. G., Pahlow, S., & Popp, J. (2020). "The Bouguer-Beer-Lambert Law: Shining Light on the Obscure". ChemPhysChem, 21(18): 2029-2046.
Kihesabu chetu cha Sheria ya Beer-Lambert kinatoa njia rahisi lakini yenye nguvu ya kuhesabu unyonyaji kulingana na urefu wa njia, uwezo wa unyonyaji wa molar, na mkusanyiko. Iwe wewe ni mwanafunzi, mtafiti, au mtaalamu wa sekta, chombo hiki kinakusaidia kutumia kanuni za msingi za spectroscopy kwa mahitaji yako maalum. Jaribu sasa ili haraka na kwa usahihi kubaini thamani za unyonyaji kwa suluhisho zako!
Gundua zana zaidi ambazo zinaweza kuwa na manufaa kwa mtiririko wako wa kazi