1.3 chemical calculations Flashcards
(10 cards)
Describe the 4 main steps about how the mass spectra works:
Ionisation= The vaporised sample passes into the ionisation chamber. Then the particles in the sample is bombarded by a stream of electrons, causing some collisions to knock one or more electrons out of the particle to make positive ions.
Acceleration= An electric field accelerates the positive ions to high speed
Deflection= Different ions are deflected by the magnetic field by different amounts. it depends on, mass of ion and charge.
Detection= The beam of ions passing through is electrically detected. (ions that collide with the walls where they will pick up electrons will be neutralised and removed by the vacuum pump). The signal is amplified and recorded.
What are some other uses of mass spectrometry?
- Identifying unknown compounds
- Identifying trace compounds in forensic science
- Analysing molecules in space
What is meant by the term relative atomic mass?
The average mass of one atom of the element relative to one-twelfth the mass of one carbon-12 atom
What is meant by the term relative isotopic mass?
The mass of an atom of an isotope relative to one twelfth the mass of a carbon-12 atom
What is meant by the term relative formula mass?
The average mass of a molecules relative to one twelfth the mass of an atom of carbon 12
What is meant by the term mole?
The amount of any substance that contains the same number of particles as there are atoms in exactly 12g of carbon 12
What is meant by the term avogadro constant?
The number of atoms per mole
What is meant by the term molar mass?
The mass of one mole of a substance
What is meant by the term empirical formula?
The simplest formula showing the simplest whole number ratio of the amount of elements present
What is meant by the term Molecular formula?
Shows the actual number of atoms of each element present in the molecule
