Analyzing Absorbance in Solutions

The video tutorial demonstrates how to use simple materials and a smartphone to teach spectrometry and Beer's Law. It explains the components of a spectrophotometer and guides viewers through setting up an experiment using a light source, sample, and light detector. The tutorial shows how to use the Colorimeter app on an iPhone to measure light absorption and analyze data in Excel to calculate the concentration of red dye in a solution. The video encourages viewers to try the experiment and engage with questions.

What are the three basic components of a spectrophotometer?

• Light source, sample, prism

• Sample, prism, light detector

• Light source, prism, light detector

• Light source, sample, light detector

What is used as the light source in the experiment setup?

• A flashlight

• Green construction paper

• A laser pointer

• A lamp

Why is it important to choose a background color that complements the solution color?

• To make the setup easier to assemble

• To ensure accurate light absorption measurements

• To enhance the visual appeal

• To match the color of the sample holder

Which app is used on the iPhone to detect light in this experiment?

• Coloro Meter

• Light Detector

• Spectro App

• Color Analyzer

What does the app measure to determine the light passing through the solution?

• The brightness of the light

• The intensity of red light

• The average RGB values

• The wavelength of light

What is the purpose of comparing the green value of a red solution to that of water?

• To find the pH level of the solution

• To measure the absorption of green light by the red dye

• To calculate the concentration of water

• To determine the color of the solution

What is the concentration of red dye in the stock solution used for the experiments?

• 4.83 micromolar

• 9.14 micromolar

• 94 micromolar

• 1.02 micromolar

How is absorbance calculated in the Excel analysis?

• By subtracting the blank's green value from the sample's green value

• By adding the green values of the sample and the blank

• By taking the negative logarithm of the sample's green value divided by the blank's green value

• By multiplying the green value of the sample by the blank

What is the slope of the line in the absorbance vs. concentration graph?

• 0.00529

• 0.529

• 0.0529

• 5.29

What is the approximate concentration of red dye in the unknown solution?

• 1.02 micromolar

• 4.85 micromolar

• 94 micromolar

• 9.14 micromolar