# Amount of substance

Includes all of the unit 2 calculations

- Created by: Georgia 753
- Created on: 20-03-16 15:42

First 184 words of the document:

Amount of Substance

Relative Atomic and Relative Molecular Mass

Atomic (Ar) Average mass of an atom/element

1

/

mass of one atom of C12

12

Molecular (Mr) Average mass of a molecule

1

/

mass of one atom of C12

12

Moles and Avogadro's Constant

A mole is the number of particles, the number of moles can be calculated by using the following

equation/triangle. This can also be used to calculate the mass (in grams) and the Mr of a compound.

Avogadro's Constant

The definition of the Avogadro's Constant/Avogadro's Number is the number of atoms in 12g of Carbom-12.

Avogadro's Number = 6.02 x 1023

Concentration of Solutions

The following equation is used for titration calculations and can be used to calculate the

volume (dm3 ), concentration or moles.

Units of Volume

1 cm3

1/1000 dm3

1 litre 1dm 3

1 ml

1/1000 dm3

Empirical Formula

This is the ratio of elements that are present in the compound in the simplest form:

## Comments