IAL Chemistry Unit 1 The Mass Spectrometer
Hosni Showike • 25 October 2024
Complete Notes for IAL Chemistry
Welcome to your essential study guide on the mass spectrometer, a key topic for your IAL Chemistry Unit 1 exam. Use these notes to deepen your understanding and prepare effectively.
Uses of the Mass Spectrometer
The mass spectrometer is a vital instrument used to accurately calculate the reactive atomic mass. It measures the mass of each isotope of an element and compares their relative abundance. Key applications include:
- Carbon Dating: Determining the age of archaeological finds.
- Blood Alcohol Measurement: Analyzing alcohol levels in forensic science.
- Pharmaceutical Purity Testing: Ensuring the quality and purity of drugs.
- Molecular Mass and Structure Determination: Identifying molecular composition and structure.

Separation of Isotopes
The mass spectrometer separates isotopes through the following steps:
- Vaporisation:
- The sample is heated to convert it into a gaseous state, allowing it to flow into the device.
2. Ionisation:
- The vaporised sample is bombarded with high-energy electrons, knocking out electrons from atoms and forming cations (mostly 1+).
3. Acceleration:
- Cations are accelerated by an electric field to ensure they have uniform speed.
4. Deflection:
- A magnetic field deflects the accelerated cations based on their mass-to-charge ratio.
- Heavier ions deflect less, while ions with higher charges deflect more.
5. Detection:
- Ions are detected on a fluorescent screen, and the mass spectrum is displayed on a computer screen as a graph

Important Considerations
These notes are designed to help you grasp the fundamental concepts and processes related to the mass spectrometer, crucial for your Unit 1 exam. Make sure to review these regularly, and best of luck with your studies!
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