Moles And Molar Mass
- "Mole is a unit of measurement used in chemistry to express amounts of a chemical substance, defined as the amount of any substance that contains as many elementary entities as there are atoms in 12 grams of pure carbon-12, the isotope of carbon with relative atomic mass of exactly 12 by definition."
Moles
Moles are used to measure mass, volume, or count pieces
1 Mole is 6.02 x 10^23- called Avogadro's number
Moles equals mass divided by molar mass
A mole is defined as the number of carbon atoms in exactly 12 grams of carbon
1 mole of a pure substance has a mass equal to its molecular mass expressed in grams.
A mole of carbon dioxide contains Avogadro's number of CO2 molecules
We measure mass in grams, volume in liters, and we count pieces in moles
This is known as the molar mass, M, and has the units g mole-1
All stoichiometry essentially is based on the evaluation of the number
of moles of substance
The convenient measurements on gases are pressure, volume, and temperature.
Use of the ideal gas law constant R allows direct calculation of the number of moles: n=P V/R T.
T is the absolute temperature, R must be chosen in units appropriate for P, V, and T
Moles are used to measure mass, volume, or count pieces
1 Mole is 6.02 x 10^23- called Avogadro's number
Moles equals mass divided by molar mass
A mole is defined as the number of carbon atoms in exactly 12 grams of carbon
1 mole of a pure substance has a mass equal to its molecular mass expressed in grams.
A mole of carbon dioxide contains Avogadro's number of CO2 molecules
We measure mass in grams, volume in liters, and we count pieces in moles
This is known as the molar mass, M, and has the units g mole-1
All stoichiometry essentially is based on the evaluation of the number
of moles of substance
The convenient measurements on gases are pressure, volume, and temperature.
Use of the ideal gas law constant R allows direct calculation of the number of moles: n=P V/R T.
T is the absolute temperature, R must be chosen in units appropriate for P, V, and T