DJA1). Amount If Substance Flashcards
Relative molecular mass / Mr
The mass of that molecule compared to 1/12 the number relative atomic mass of carbon 12
Avogadro’s constant definition
The number of particles (atoms, ions, molecules, electrons etc…) in 1 mile of substance
Avogadro’s constant symbol and number
L= 6.022x10^23 particles (don’t need to know number)
Number of particles in x number of miles of substance y…..
number = moles times L (Avogadro’s constant)
Limiting reagent=
Substance with least number of moles
Uncertainty = (number and %)
Half the smallest division
%= uncertainty divided by measurement x100
Must calculate all uncertainties in percentages then add them all together to get total percentage uncertainty
Ideal gas equation
PV=nRT
IDGE
P=
Pressure (Pa)
V
Volume (m^3)
n
Moles
R
Gas constant (Jmol^-1K^-1)
T
Temperature (K)
KPa -Pa
x1000
MPa-Pa
x1000000
dm^3 - m^3
/1000
cm^3 -m^3
/1000000
Degrees - kelvin
Degrees + 273
1 atm =
101000Pa
Gas constant=
8.31 Jmol^-1K^-1
Ideal gas has what type of particles
Point like
So when they collide no energy is lost
Molecular formula
The actual number of atoms of each element in a molecule
Empirical formula
The simples whole number ratio of atoms of each element in a compound
atom economy =
Mr of wanted product divided by Mr of products x 100
To find molecular from empirical
Empirical x Mr / formula mass of empirical
RFM/ Ar definition
The weighted average mass of an atom of an element taking into account all its naturally occurring isotopes relative to 1/12 the relative atomic mass of carbon 12
a
a
a
a
b
b
b
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