AP Chemistry Flashcards: Beer Lambert Law

What this deck covers

This deck focuses on Beer Lambert Law, giving you a quick way to review the definitions, rules, and examples that matter most for AP Chemistry.

How to use these flashcards

Work through these flashcards in short sessions. Try to answer each prompt before flipping the card, then revisit any cards you miss until the explanation feels automatic.

Flashcard 1: What type of samples are best measured with Beer-Lambert Law?

Answer: Clear and homogeneous solutions. Non-scattering samples give most accurate Beer-Lambert results.

Flashcard 2: What does a spectrophotometer measure directly?

Answer: Intensity of light passing through a sample. Measures transmitted light intensity to calculate absorbance.

Flashcard 3: What is the absorbance at 50% transmittance?

Answer: Absorbance $A = 0.3$. Using $A = -\text{log}_{10}(0.5) \approx 0.3$.

Flashcard 4: What is the result of absorbance measurement if the solution is turbid?

Answer: Absorbance may be inaccurately high. Turbidity scatters light, appearing as additional absorption.

Flashcard 5: What does $\text{c}$ represent in the Beer-Lambert Law?

Answer: Concentration of the solution. Molarity of the absorbing species in solution.

Flashcard 6: What type of samples are best measured with Beer-Lambert Law?

Answer: Clear and homogeneous solutions. Non-scattering samples give most accurate Beer-Lambert results.

Flashcard 7: What does a spectrophotometer measure directly?

Answer: Intensity of light passing through a sample. Measures transmitted light intensity to calculate absorbance.

Flashcard 8: What is the absorbance at 50% transmittance?

Answer: Absorbance $A = 0.3$. Using $A = -\text{log}_{10}(0.5) \approx 0.3$.

Flashcard 9: What does $\text{c}$ represent in the Beer-Lambert Law?

Answer: Concentration of the solution. Molarity of the absorbing species in solution.

Flashcard 10: What type of samples are best measured with Beer-Lambert Law?

Answer: Clear and homogeneous solutions. Non-scattering samples give most accurate Beer-Lambert results.

Flashcard 11: What does a spectrophotometer measure directly?

Answer: Intensity of light passing through a sample. Measures transmitted light intensity to calculate absorbance.

Flashcard 12: What is the absorbance at 50% transmittance?

Answer: Absorbance $A = 0.3$. Using $A = -\text{log}_{10}(0.5) \approx 0.3$.

Flashcard 13: What does $\text{c}$ represent in the Beer-Lambert Law?

Answer: Concentration of the solution. Molarity of the absorbing species in solution.

Flashcard 14: State the range of absorbance values for most accurate measurements.

Answer: Between 0.1 and 1. Range where detector response is most linear and precise.

Flashcard 15: What is the effect of scattering on Beer-Lambert Law?

Answer: Causes deviations from linearity. Scattered light doesn't follow absorption laws, affecting accuracy.

Flashcard 16: Calculate transmittance if absorbance is 1.

Answer: Transmittance $T = 0.1$ or 10%. Using $T = 10^{-A} = 10^{-1} = 0.1$.

Flashcard 17: If $\text{c} = 0$, what is the absorbance?

Answer: Absorbance $A = 0$. Zero concentration means no absorbing species present.

Flashcard 18: Identify the effect of instrument limitations on Beer-Lambert Law.

Answer: Potential for measurement errors. Detector noise and drift can introduce systematic errors.

Flashcard 19: Calculate absorbance if $\text{ε} = 1 \text{L mol}^{-1} \text{cm}^{-1}$, $\text{c} = 1 \text{mol L}^{-1}$, $\text{l} = 2 \text{cm}$.

Answer: Absorbance $A = 2$. Substituting values: $A = 1 \times 1 \times 2 = 2$.

Flashcard 20: What condition must be met for the path length in Beer-Lambert Law?

Answer: Path length must be uniform. Variable path length would invalidate the linear relationship.

Flashcard 21: What property of a solution does the Beer-Lambert Law describe?

Answer: Absorbance. Quantifies how much light a solution absorbs at specific wavelengths.

Flashcard 22: State the equation for transmittance $T$.

Answer: $T = \frac{I}{I_0}$. Ratio of transmitted light intensity to incident intensity.

Flashcard 23: How is absorbance measured in a spectrophotometer?

Answer: Using a specific wavelength of light. Monochromatic light ensures consistent molar absorptivity values.

Flashcard 24: What is the absorbance if transmittance is 100%?

Answer: Absorbance is 0. Complete transmission means no light absorption occurred.

Flashcard 25: What type of relationship exists between absorbance and concentration?

Answer: Linear relationship. Direct proportionality as described by Beer-Lambert Law.

Flashcard 26: How does absorbance change with increasing concentration?

Answer: Absorbance increases. Direct proportional relationship according to Beer-Lambert Law.

Flashcard 27: What is the result of absorbance measurement if the solution is turbid?

Answer: Absorbance may be inaccurately high. Turbidity scatters light, appearing as additional absorption.

Flashcard 28: If $I_0 = 100$ and $I = 10$, what is the absorbance?

Answer: Absorbance $A = 1$. Using $A = -\text{log}_{10}(0.1) = 1$.

Flashcard 29: What is the relationship between absorbance and transmittance?

Answer: $A = -\text{log}_{10}(T)$, where $T = \frac{I}{I_0}$. Absorbance is negative log of transmittance fraction.

Flashcard 30: If $I_0 = 100$ and $I = 10$, what is the transmittance?

Answer: Transmittance $T = 0.1$ or 10%. Transmittance equals $\frac{I}{I_0} = \frac{10}{100} = 0.1$.