Calculations Flashcards
What is the calculation for Ar?
Ar = ((Mass x %) + (Mass x %)) / 100
What is the reverse calculation for Ar?
Ar = ((Mass x X) + (Mass x 100-X)) / 100
What is the calculation to find the abundance of one isotope?
Ar = ((Mass x %) + (Mass x X)) / 100
How do you calculate the empirical formula?
Divide by the Ar of the element. Divide by the lowest answer. Multiply through is necessary. Write the empirical formula.
What is the equation for percentage mass?
Percentage mass = (number of atoms x Ar of element) / Mr of compound
What is the equation for moles?
Moles = mass (g) / Mr
What is the gas equation for moles in dm^3?
Moles = volume (dm^3) / 24
What is the gas equation for moles in cm^3
Moles = volume (cm^3) / 24000
What is the ideal gas equation?
Pressure (Pa) x Volume (m^3) = moles of gas x gas constant x temperature (K)
PV = nRT
Gas constant = 8.314Jmole-1K-1
What is the number of particles equation?
No particles = no moles x no of particles in formula unit x (6.02 x 10^23)
What is the reverse equation for the number of particles?
no moles = no of molecules / 6.02x10^23
mass = Mr x mol
What are the equations for moles of a solution?
Moles = Concentration (moldm^-3) x volume (dm^3)
Moles = (Concentration (moldm^-3) x volume (cm^3)) / 1000
What is the equation for percentage purity?
Percentage purity = (mass/total mass) x 100
