Atoms And Moles Module 2 Section 1 /2 Flashcards
What is relative atomic mass
The average mass of an atom of an element compared to 1/12 of the mass of an atom of carbon-12
Relative formula mass
The average mass of a molecule or formula unit compared to 1/12 of the mass of an atom of carbon-12
Relative isotopic mass
The mass of an atom of an isotope of an element compared to 1/12 of the mass of an atom of carbon-12
Relative molecular mass
The average mass of an molecule compared to 1/12 of the mass of an atom of carbon-12
What are isotopes
Atoms with Same number of protons different number of neutrons
What does the term amount of substance mean
Number of particles
Avogadro constant
6.02x10 ^23 particles in one mole
Molar mass
Mass of 1 mole of something
Units g mol -1
Equation for gas volumes
Long equation
pV= nRT
P- pressure (pa)
V- volume m3
N- number of moles
R- gas constant ( j k-1 mol-1) always 8.314 !!!
T- temperature (k)
How to convert degrees to kelvin
Add 273 to value in degrees
E.g 25 degrees = 298k
Gas volume equation
Number of moles = volume dm3
_____________
24
Number of moles =
Gas
Number of moles = volume cm3
—————
24000
Number of moles calculation from number of atoms / molecules
N.o particles you have
————————— = N.0 moles
N.p particles in a mole
( 6.02x10^23)
Molar mass and formula mass of caCO3
Formula mass = 40.1 + 12 + (3x16) =100.1
Molar mass = 100.1g mol -1
Number of moles
Solid
Mass of substance
————————- = n.0 moles
Molar mass
