AP Chemistry Flashcards: Mass Spectra Of Elements

What this deck covers

This deck focuses on Mass Spectra Of Elements, 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: Determine the isotopic composition of chlorine using its mass spectrum.

Answer: Peaks at m/z = 35 and 37. Shows $^{35}$Cl and $^{37}$Cl isotopes in 3:1 ratio.

Flashcard 2: How is the molecular ion peak identified in a mass spectrum?

Answer: It is the peak with the highest m/z value. The rightmost peak shows the intact molecule's mass.

Flashcard 3: What is the typical charge state observed in a mass spectrum?

Answer: +1. Most ions have single positive charge from electron loss.

Flashcard 4: What does a cluster of peaks in a mass spectrum suggest?

Answer: Presence of isotopic variants. Multiple isotopes create pattern of related peaks.

Flashcard 5: Determine the presence of sulfur isotopes in a mass spectrum.

Answer: Look for peaks at m/z = 32, 33, 34. Sulfur has isotopes $^{32}$S, $^{33}$S, and $^{34}$S.

Flashcard 6: What can cause broad peaks in a mass spectrum?

Answer: Instrumental resolution limitations. Poor resolution cannot separate closely spaced m/z values.

Flashcard 7: How can isotopic ratios be determined from a mass spectrum?

Answer: By comparing relative peak heights. Peak height ratios show isotopic abundance ratios.

Flashcard 8: Identify the peak corresponding to the molecular ion of methane (CH₄).

Answer: Peak at m/z = 16. Methane molecular ion has mass 16 amu.

Flashcard 9: How does a mass spectrometer identify different isotopes?

Answer: By their distinct m/z values. Each isotope has unique mass giving distinct m/z value.

Flashcard 10: What is the function of the magnetic field in a mass spectrometer?

Answer: To deflect ions based on m/z. Creates force that separates ions by mass-to-charge ratio.

Flashcard 11: What does a low abundance peak in a mass spectrum indicate?

Answer: Less common isotope or fragment. Shows minor isotope or molecular fragmentation product.

Flashcard 12: Which factor affects the degree of ion deflection in a mass spectrometer?

Answer: Mass-to-charge ratio (m/z). Determines how much ions deflect in the magnetic field.

Flashcard 13: Which element's isotopes can be separated using mass spectrometry?

Answer: Any element with isotopes. Mass spectrometry can separate isotopes of all elements.

Flashcard 14: What is the charge of ions detected in a mass spectrometer?

Answer: Typically +1 charge. Single positive charge from electron removal during ionization.

Flashcard 15: Describe the main stages of a mass spectrometer.

Answer: Ionization, acceleration, deflection, detection. Sequential steps that separate and detect ions by mass.

Flashcard 16: What is the role of acceleration in mass spectrometry?

Answer: To give ions kinetic energy. Accelerated ions can be deflected by magnetic fields.

Flashcard 17: What does the x-axis represent in a mass spectrum?

Answer: Mass-to-charge ratio (m/z). Shows the mass divided by charge for each ion detected.

Flashcard 18: Identify the ionization method used in mass spectrometry.

Answer: Electron impact ionization. High-energy electrons remove electrons from atoms/molecules.

Flashcard 19: How are ions detected in a mass spectrometer?

Answer: By measuring their abundance as electrical signals. Ion collisions create electrical current proportional to abundance.

Flashcard 20: What information does a mass spectrum provide about an element?

Answer: Isotopic composition and abundance. Shows which isotopes exist and their relative amounts.

Flashcard 21: What is the purpose of the detector in a mass spectrometer?

Answer: To measure the abundance of ions. Converts ion impacts into measurable electrical signals.

Flashcard 22: What does the term 'base peak' mean in mass spectrometry?

Answer: The tallest peak representing 100% relative abundance. The peak set to 100% for comparing other peak heights.

Flashcard 23: What is the unit for mass-to-charge ratio in mass spectrometry?

Answer: Atomic mass units per charge (amu/e). Standard unit expressing mass per unit charge.

Flashcard 24: How is the resolution of a mass spectrometer defined?

Answer: Ability to distinguish between close m/z values. Measures ability to separate peaks with similar m/z values.

Flashcard 25: Find the relative atomic mass given isotopic masses and abundances.

Answer: Calculate using $\text{RAM} = \frac{\text{sum of (m/z) × abundance}}{\text{total abundance}}$. Weighted average formula using isotopic masses and abundances.

Flashcard 26: Which isotope of carbon is most abundant, based on mass spectra?

Answer: $^{12}$C. The most abundant carbon isotope in nature.

Flashcard 27: What does a peak at m/z = 16 indicate in an oxygen mass spectrum?

Answer: $^{16}$O isotope. The most abundant oxygen isotope with mass 16 amu.

Flashcard 28: What can cause isotopic peaks to appear at higher m/z values?

Answer: Presence of heavier isotopes. Higher mass isotopes have greater m/z values.

Flashcard 29: What is the significance of the largest peak in a mass spectrum?

Answer: It represents the most abundant isotope. The base peak shows which isotope has the highest natural abundance.

Flashcard 30: How does the mass spectrometer separate isotopes?

Answer: By deflecting ions based on mass-to-charge ratio. Magnetic field deflects ions differently based on their m/z ratio.