mod 4 mole.pptx
- 2. Module 4: What¡¯s in a MOLE 1. How is the mole used to express the mass of a substance? 2. How is the percentage composition of a given compound determined? Objectives: ? use the mole concept to express mass substances; and ? Determine the percentage composition of a compound given its chemical formula and vice versa
- 3. ? Given the SI symbol mol and is equivalent to Avogadro¡¯s number, 6.02X1023 particles ? Particles can be atoms, molecules, or formula units. ? One mole of different substances always contains 6.02X1023 particles but each of these substances has a different mass ? Lorenzo Romano Amedeo Carlo Avogadro (1776-1856), Italian scientist ? First suggested that it might be possible to count atoms ? Established a law stating that equal volumes of gases contain the same number of molecules at the same temperature and pressure. MOLE
- 4. The interconversion of mass, mole, and number of particles of an element mass No. of moles No. of particles Divide by Molar mass Multiply by Multiply by Avogadro¡¯s # Divide by
- 5. MATTER Particles Avogadro¡¯s # A mole g/mol molecules ions atoms Is made up of W/c may be Whose amount may be expressed in terms of Whose mass is expressed in Equal to
- 6. Percentage composition of a Compound ? The mass of each element in a compound compared to the entire mass of the compound multiplied by 100 percent ? Tells the percentage of the mass made up by each element in a compound % composition = mass of component element X 100 mass for molar mass of compound