Topic 8 Chemical Analysis
No description yet. This curated deck is ready for daily study.
Card preview (12)
Q: What defines a pure substance?
a single element or compound, with sharp melting/boiling points.
Q: How does an impurity affect melting and boiling points?
A: Lowers melting point, raises boiling point which makes it occur over a range.
Q: What is a formulation?
A: A mixture designed for a specific purpose
Q: Give examples of formulations.
paint,fuels,cleaning products,medicines
Q: What is chromatography used for?
A: Separating and identifying components of a mixture.
Q: How is an Rf value calculated?
A: Distance moved by substance ÷ distance moved by solvent.
Why are instrumental methods better than chemical tests?
More accurate, faster, can detect small amounts, and identify substances in mixtures.
Q: Examples of instrumental methods?
A: Gas chromatography (GC), Mass spectrometry (MS), GC-MS combined.
What is flame emission spectroscopy used for?
Identifying metal ions by their light emission patterns.
Why is pencil used in chromatography?
It doesn’t dissolve in the solvent.
What does a single spot mean?
Pure substance.