2.1 Atoms and reactions Flashcards
Isotopes
atoms of the same element with different numbers of neutrons and different masses
Relative isotopic mass
mass (of an isotope) compared with 1/12th the mass of carbon-12
Relative atomic mass, Ar
weighted mean mass (of an atom) compared with 1/12th the mass of carbon-12
What are the two uses of mass spectrometry?
- determining relative isotopic masses and relative abundances of the isotope
- calculating the relative atomic mass of an element from the relative abundances of its isotopes
Relative molecular mass, Mr (def not req)
when used?
weighted mean mass (of a molecule) compared with 1/12th the mass of carbon-12
- used for simple molecules
Relative formula mass, Mr (def not req)
when used?
weighted mean mass (of a formula unit) compared with 1/12th the mass of carbon-12
- used for compounds with giant structures
Calcium ion
Ca2+
Caesium ion
Cs+
Fluoride ion
F-
Sulfide ion
S2-
Nitride ion
N3-
Silver ion
Ag+
Ammonium ion
NH4+
Zinc ion
Zn2+
Lead ion
Pb2+
state the ideal gas equation
pV=nRT
Solute (def not req)
substance of any state which dissolves in a solvent
Solvent (def not req)
liquid in which a solute is dissolved
Standard solution
a solution of known concentration
what are the standard units for pressure, volume, temp, and amount in the ideal gas equation? (pV=nRT)
pressure in Pa
volume in m3
temp in K
amount in mol
1 atm = …..Pa
101000Pa
percentage yield =
actual yield of product (mol) / theoretical yield of product (mol) x100
atom economy =
M of desired products / M of all products x 100
how can you improve % yield?
- use better conditions
- recycle unreacted products
- if reversible, remove products after made (so they’re not turned back into reactants)
why is developing chemical processes with a high atom economy sustainable?
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