Amount of Substance Flashcards
(13 cards)
Define relative atomic mass (Ar).
The mean mass of an atom of an element, divided by 1/12 of the mean mass of an atom of the carbon 12 isotope.
Define relative molecular mass (Mr).
The mean mass of a molecule or compound, divided by 1/12 of the mean mass of an atom on the carbon 12 isotope.
What is Avogadro’s constant?
6.022x10^23
How to calculate number of particles present in a substance?
number of particles= moles x Avogadro’s constant
How to calculate moles using mass and Mr?
Moles= mass/ Mr
How to calculate moles using concentration and volume?
Moles= concentration x volume
What is the ideal gas equation?
PV= nRT
Pressure= in Pascals
Volume=m^3
Temperature= Kelvin
Mass=grams
Moles=Moles
R= 8.31Jk^-1mol^-1
What are the standard conditions for ideal gas equation?
Pressure is proportional to temperature.
Volume is proportional to temperature.
Pressure and volume are inversely proportional.
What is empirical formula?
The simplest whole number ratio of atoms of each element in a compound. It is found using molar ratios of each element
What is molecular formula?
The true number of each atom in the molecule.
How can you find the Mr of a molecule using a multiplier and empirical Mr?
Mr of molecule= multiplier x Empirical Mr
How do you find % Yield?
% Yield= (Real mass/ Theoretical mass) x100
How do you find % Atom economy?
% Atom economy = (Mr of desired product/ Mr of all products) x 100
