Module 2 Flashcards
Isotope definition
Atoms of the same element with different numbers of neutrons and different masses
Cations
Positive ions
Anions
Negative ions
Relative isotopic mass
Is the mass of an isotope relative to 1/12 th of the mass of an atom of carbon-12
Relative atomic mass
The weighted mean mass of an atom of an element relative to 1/12 of the mass of an atom of carbon-12
Mass to charge ratio (m/z) equation
Relative mass of ion / relative charge of ion
Relative atomic mass equation
(Abundance x mass) (abundance x mass) … / 100
Avogadros constant
6l02x10^23, the number of particles in each mole of carbon-12
Mol equation
Mol= mass/ mr
Molecular formula definition
The number of atoms of each element in a molecule
Empirical formula
The simplest whole number ratio of atoms of each element in a compound
mol equation ( from c and v )
Mol= conc x vol
Standard solution
A solution of known concentration. They are made by dissolving an exact mass of the solute in a solvent and making up the solution to an exact volume
Mol equation at rtp
Mol= vol (dm3) / 24
Ideal gas equation
pV= nRT
Value for the gas constant
8.314 j mol k
How to convert from cm3 to m3
X10^-6
How to convert from c to k
+ 273
Percentage yield
Actual yield / theoretical yield x 100
Theoretical yield
The maximum possible amount of product
Why isn’t the theoretical yield always reached
The reaction may not have been completely reacted
Side reactions may have taken place
Purification of the product may result in loss of some product
Actual yield
Obtained from a reaction is usually lower then the theoretical yield
Limiting reagent
The reactant that’s not in excess and when it’s completely used up first it stops the reaction
Atom economy
Sum of mr of desired product / sum of mr of all products X 100
Oxidation number for element s
0
Oxidation number of H in hydrides (eg NaH, CaH2)
-1