Untitled Deck Flashcards
What does Thermogravimetric Analysis (TGA) measure?
Mass change of a substance as the temperature increases
What are the main components of TGA instrumentation?
- Sample holder
- Environment control
- Furnace
- Analytical balance
- Thermocouple
- Amplifier
- Recorder
List some applications of Thermogravimetric Analysis (TGA).
- Determines stability
- Purity
- Decomposition mechanisms
- Filler content
- Adulteration in food
- Metal content in alloys
At what temperature does PVC decompose according to TGA?
At lower temperatures
At what temperature does PTFE decompose according to TGA?
600°C
What principle does X-Ray Diffraction (XRD) rely on?
Bragg’s Law
What does Bragg’s Law relate to in XRD?
- X-ray wavelength
- Crystal plane distance
- Diffraction angle
What are the main components of XRD instrumentation?
- X-ray tube
- Collimator
- Sample holder
- Detectors (photographic or counter)
List some applications of X-Ray Diffraction (XRD).
- Studies grain size
- Phase identification
- Crystal structure in materials
- Polymers
- Drugs
- Nanoparticles
What principle does Scanning Electron Microscopy (SEM) operate on?
Electron beam scans the sample producing secondary and backscattered electrons
What information does SEM provide?
- Topographic information
- Compositional information
What are the main components of SEM instrumentation?
- Electron source
- Condenser lens
- Anode
- Scan coils
- Objective lens
- Sample chamber
- Detectors
List some applications of Scanning Electron Microscopy (SEM).
- Characterizes surface morphology
- Particle size
- Composition
- Crystallographic information
What principle do Potentiometric Titrations use?
Measures electrode potential changes during titration
What is an application of Potentiometric Titrations?
Estimation of Fe²⁺ ions using K₂Cr₂O₇ as an oxidizing agent
What principle do Conductometric Titrations use?
Measures conductance changes during titration
What types of mixtures are Conductometric Titrations particularly useful for?
Strong acid-weak acid mixtures
What can Conductometric Titrations determine?
- Neutralization points
- Degree of ionization
