Section 2, Unit 2 Mixtures and Separation Techniques

Separating These Mixtures – Separation Techniques target the components’ differences in physical properties. Review: What are Physical Properties? Filtration- Evaporation- Chromatography- Distillation- Centrifugation –

Pure or Impure Chemists Classify Matter As Pure or Impure – Pure – If the material consists of only a single element or a single compound – Impure – If the mixture contains two or more elements or compounds

Pure or Impure Flow Chart

Pure or Impure Mixtures can be either Homogeneous or Heterogeneous

Heterogeneous Mixture Heterogeneous Mixture – The different components can be seen as individual substances Examples – “Snow” in a snow globe – Pizza – Pulp in Orange Juice – Any Others??

Homogeneous Mixture Homogeneous Mixture – Has the same composition throughout. You can take multiple samples from different locations and the compositions will be the exact same. Examples: Air Seawater Kool-Aid

Separation How can you separate these solutions?? – Milk (proteins are suspended in solution) – Blood (cells and proteins are suspended in solution) – ___________________ » Yields two layers (solution on top, suspensions on bottom)

Atoms are the Fundamental Components of Elements – The Periodic Table contains a relatively small number of atoms that form an unlimited number of different materials. This is based on how they combine or bond together

Atoms are the Fundamental Components of Elements – The Periodic Table contains a relatively small number of atoms that form an unlimited number of different materials. This is based on how they combine or bond together – Element – Any material consisting of only one type of atom. – Atom – Submicroscopic particles in a sample. Each element is designated by a symbol (Atomic Symbol) Co =/= CO, only the first letter is capital

Atoms are the Fundamental Components of Elements – Elemental Formula – How many atoms are bonded together in an element Au = Goldii. N 2 = Nitrogeniii. Ni = Nickel – Seven Diatomic Elements: – Oxygen, Hydrogen, Nitrogen, Bromine, Chlorine, Iodine, Fluorine – How about diatomic oxygen vs. ozone, O 3 ? – Are they the same? – No, BUT both are elemental forms of oxygen

Combining Elements to Form Compounds – Molecule- Consists of two or more atoms combined in a definite ratio – Compound– Atoms of different elements bound to one another – We had an Elemental Formula for elements, how will we represent chemicals bound together to form chemical compounds?

Combining Elements to Form Compounds – Chemical Formula – How much of what is in the compound (symbols and subscripts) NaCl: One sodium per chlorine atom MgCl 2 : One magnesium per two chlorine atoms

Combining Elements to Form Compounds – Hydrogen Sulfide is one of the smelliest compounds. Rotten eggs get their characteristic bad smell from the hydrogen sulfide that they release. Can you infer from this information that elemental sulfur is just as smelly? – *Compounds have Physical and Chemical properties that are different from the properties of their elemental compounds

“Separation Techniques” lab tomorrow – dress appropriately.