CHM2046L Final Exam
What is emitted during gamma decay? High-energy photon (γ ray), no change in mass or atomic number
Which type of radiation is the most penetrating? Gamma rays
What blocks alpha particles? Paper
What blocks beta particles? Aluminum sheet
What can partially block gamma rays? Thick lead, dense concrete
What is the order of radioactive decay reactions? First-order reactions
What graph is linear for a first-order reaction? ln[A] vs time
What is the formula for half-life in first-order kinetics? t₁/₂ = 0.693 ÷ k
What is the formula to calculate the percent error? (|measured - true| ÷ true) × 100
What does accuracy refer to? How close a measurement is to the true value
What does precision refer to? How close repeated measurements are to each other
What type of error affects accuracy? Systematic error
What type of error affects precision? Random error
What safety precautions must you take with radioactive Wear gloves, wear goggles, wear lab coat, use shielding, minimize exposure
materials? time
What does Beer's Law state? Absorbance is directly proportional to concentration
What is the equation for Beer's Law? A = εbc
In Beer's Law, what does A represent? Absorbance
, CHM2046L Final Exam
In Beer's Law, what does ε represent? Molar absorptivity
In Beer's Law, what does b represent? Path length of the cuvette in cm
In Beer's Law, what does c represent? Concentration of the solution
What happens to absorbance as concentration Absorbance increases
increases?
If a solution appears blue, what wavelength of light is it Orange, around 620 nm
absorbing?
What unit is typically used for concentration in Beer's Molarity (M)
Law?
What unit is path length usually measured in? Centimeters (cm)
What does a calibration curve plot in Beer's Law? Absorbance vs Concentration
What does the slope of the calibration curve Molar absorptivity (ε) if b = 1 cm
represent?
What kind of relationship is expected between Linear
absorbance and concentration?
How do you calculate unknown concentration from a Use the line equation, solve for concentration from absorbance
calibration curve?
What is a serial dilution? Stepwise dilution of a solution to achieve lower concentrations
What happens to Beer's Law at very high Deviations occur, absorbance may not increase linearly
concentrations?
What happens to Beer's Law at very low Absorbance may be too small to measure accurately
concentrations?
How do you prepare a diluted solution? Use M₁V₁ = M₂V₂
How do you find how much stock solution to use for a V₁ = (M₂ × V₂) ÷ M₁
dilution?
If a solution has an absorbance of 0.756 and the 22.48 micromolar
calibration line is y = 33499x + 0.0012, what is the
concentration?
What is emitted during gamma decay? High-energy photon (γ ray), no change in mass or atomic number
Which type of radiation is the most penetrating? Gamma rays
What blocks alpha particles? Paper
What blocks beta particles? Aluminum sheet
What can partially block gamma rays? Thick lead, dense concrete
What is the order of radioactive decay reactions? First-order reactions
What graph is linear for a first-order reaction? ln[A] vs time
What is the formula for half-life in first-order kinetics? t₁/₂ = 0.693 ÷ k
What is the formula to calculate the percent error? (|measured - true| ÷ true) × 100
What does accuracy refer to? How close a measurement is to the true value
What does precision refer to? How close repeated measurements are to each other
What type of error affects accuracy? Systematic error
What type of error affects precision? Random error
What safety precautions must you take with radioactive Wear gloves, wear goggles, wear lab coat, use shielding, minimize exposure
materials? time
What does Beer's Law state? Absorbance is directly proportional to concentration
What is the equation for Beer's Law? A = εbc
In Beer's Law, what does A represent? Absorbance
, CHM2046L Final Exam
In Beer's Law, what does ε represent? Molar absorptivity
In Beer's Law, what does b represent? Path length of the cuvette in cm
In Beer's Law, what does c represent? Concentration of the solution
What happens to absorbance as concentration Absorbance increases
increases?
If a solution appears blue, what wavelength of light is it Orange, around 620 nm
absorbing?
What unit is typically used for concentration in Beer's Molarity (M)
Law?
What unit is path length usually measured in? Centimeters (cm)
What does a calibration curve plot in Beer's Law? Absorbance vs Concentration
What does the slope of the calibration curve Molar absorptivity (ε) if b = 1 cm
represent?
What kind of relationship is expected between Linear
absorbance and concentration?
How do you calculate unknown concentration from a Use the line equation, solve for concentration from absorbance
calibration curve?
What is a serial dilution? Stepwise dilution of a solution to achieve lower concentrations
What happens to Beer's Law at very high Deviations occur, absorbance may not increase linearly
concentrations?
What happens to Beer's Law at very low Absorbance may be too small to measure accurately
concentrations?
How do you prepare a diluted solution? Use M₁V₁ = M₂V₂
How do you find how much stock solution to use for a V₁ = (M₂ × V₂) ÷ M₁
dilution?
If a solution has an absorbance of 0.756 and the 22.48 micromolar
calibration line is y = 33499x + 0.0012, what is the
concentration?
