Moles & Concentrations
What is a Mole:
The mole can be used to measure the amount of a substance. One mole contains 6.02 x 1023
particles. This number is known as Avogadro’s number/constant.
Number of particles = Number of Moles x Avogadro’s Number
Calculating Moles:
The mass of 1 mole of any substance is equal to its relative formula mass in grams.
Number of Moles = Mass / Mr
Mole units = mol
Mass units = grams
Calculating Moles of Gases:
The number of moles in a certain volume of gas can be calculated by using the ideal gas
equation:
pV=nRT Where:
• p = pressure (Pa)
• V = volume (m3)
• n = moles
• R = 8.31 (gas constant) (J K-1 mol-1)
• T = temperature (K)
Calculating Concentrations:
The concentration of a solution is how many moles are dissolved per 1dm3.
Concentration (mol dm-3) = Moles (mol) / Volume (dm3)
A standard solution is any solution you know the exact concentration of.
What is a Mole:
The mole can be used to measure the amount of a substance. One mole contains 6.02 x 1023
particles. This number is known as Avogadro’s number/constant.
Number of particles = Number of Moles x Avogadro’s Number
Calculating Moles:
The mass of 1 mole of any substance is equal to its relative formula mass in grams.
Number of Moles = Mass / Mr
Mole units = mol
Mass units = grams
Calculating Moles of Gases:
The number of moles in a certain volume of gas can be calculated by using the ideal gas
equation:
pV=nRT Where:
• p = pressure (Pa)
• V = volume (m3)
• n = moles
• R = 8.31 (gas constant) (J K-1 mol-1)
• T = temperature (K)
Calculating Concentrations:
The concentration of a solution is how many moles are dissolved per 1dm3.
Concentration (mol dm-3) = Moles (mol) / Volume (dm3)
A standard solution is any solution you know the exact concentration of.
