Physical Flashcards
How to go from mass of one mole in TOF to mass of one atom
Divide weight of one mole (grams) by the Avogadro constant
How does electrospray ionisation create a charged particle?
Sample dissolved in volatile solvent
Injected through a hypodermic needle giving a fine mist
Tip of needle has a high voltage
Gains a proton
How does electron gun ionisation create a charged particle?
High energy electrons
From electron gun
Fired at sample
Knocks off one electron
Why would you get very low M/Z peaks in TOF?
Due to fragmentation
Define relative atomic mass
Mean mass of an atom of an element
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1/12 the mass of an atom of carbon-12
Define relative molecular mass
Mean mass of a molecule of a compound
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1/12 mass of an atom of carbon-12 isotope
Define Lattice enthalpy of dissociation
The energy required to break apart an ionic lattice into its constituent ions in a gaseous state under standard conditions
Define lattice enthalpy of formation
The energy required to form an ionic lattice from constituent ions in a gaseous state under standard conditions
Define atomisation enthalpy
The energy required for the formation of a mole of gaseous atoms under standard conditions
Define enthalpy of electron affinity
The enthalpy change when one mole of 1- gaseous ions is formed from 1 mole of gaseous atoms under standard conditions
Define enthalpy of solution
The enthalpy change when one mole of ionic solid is dissolved in water to infinite dilution so that ions no longer interact under standard conditions
Enthalpy of hydration
The enthalpy change when one mole of gaseous ions are dissolved in water to form one mole of aqueous ions under standard conditions
Define entropy
Number of possible arrangements of the particles and their energy in a given system
What is a substitute for rate on graphs?
1/T
What is a buffer?
A solution that resists changes in pH when small amounts of acid or alkali are added
