Chemistry- Moles(Chapter 5)

Mole/Molar Mass

One mole of particles is obtained by weighing out the Ar or Mr of the substance in grams. The number of particles in a mole is 6.02×10²³ Molar Mass = Mass of one mole

Avogadro’s Law

A gas with the same pressure and temperature takes up the same volume. at rtp this is 24 dm3.

Mole Calculation Triangle

Mass(g)/Molar mass * No of moles

Gas Volume Calculation Triangle

Volume(dm3)/No of moles *24dm3

Concentration

The concentration of a solution is the amount of solute(in g or mol) dissolved in 1dm3 of solution.

Concentration Calculation

mol of solute/concentration*volume

Empirical Formula

A formula of a compound with the simplest ratio of combination. The empirical and molecular formulas are the same for ionic compunds.

Molecular Formula

The formula of a compound using the number of atoms that actually combine.

Equation to Find Molecular Formula

Mr/Empirical mass=n n*number in empirical formula

% Yield

Found by dividing the actual mass of products by the theoretical mass(calculated by Mr) multiplied by 100. it gives a percentage

% Purity

Found by dividing the mass of pure substance by the mass of impure substance x 100. it gives a percentage.