How Your Lab Graph Shows Beer’s Law | Absorbance vs Concentration Explained!

In this video, I connect your absorbance vs. concentration graph to Beer’s Law and explain what the trendline equation actually means.

00:00 Intro – How your lab graph shows Beer’s Law
00:29 Slope-intercept form: y = mx + b
00:46 Beer’s Law: A = εbc
01:04 Why absorbance is y and concentration is x
01:33 What the trendline slope means (ε × path length)
01:55 Why path length is usually 1 cm
02:21 Why the slope equals ε
02:38 What the y-intercept really means
03:25 Determining molar absorptivity from the graph
04:12 Using the trendline to find an unknown concentration

We’ll compare the slope-intercept form of a line (y=mx+b) to Beer’s Law (A=εbc) so you can clearly see:

🧪 Why absorbance is plotted on the y-axis
🧪Why concentration is on the x-axis
🧪What the slope of the graph represents
🧪Why your trendline has a y-intercept, even though Beer’s Law doesn’t

This video is a continuation of my previous lesson on plotting absorbance vs. concentration, and it’s especially helpful for general chemistry and biochemistry lab students who are confused about calibration curves and Beer’s Law.

💡 By the end, you’ll understand how your experimental data connects directly to the theory behind Beer’s Law - and how to interpret your graph with confidence.

#BeersLaw, #GeneralChemistry, #ChemistryLab, #Absorbance, #CalibrationCurve, #Biochemistry, #ChemHelp