1 05.2015 301 Matter: Classifications and State

301 Matter: Classification and States

Dr. Fred Omega Garces General Chemistry

Chemistry 152

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Classification of matter? • Elements, • compound, • mixture, ...

Three (actually 4) states of matter. • Solid-fix shape, fix volume • Liquid- shape container, fix volume • Gas- shape container , volume container

Distinguishing physical & chemical properties. - Identity retain vs. new identity

The Essence of Matter (review)

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Classification of Matter

How is the universe classified ?

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Examples of Matter’s Classification Here are some examples of minerals found on earth and how they each may be classified: Heterogeneous:

•Granite •Muddy water

Homogeneous •Gold Alloy

Compound •Emerald •Epson salt (MgSO4)

Element •Silver •Graphite

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Consider the following: Determining Class of Matter

Consider the following Substances -Classify each material and state phase of matter. -Come up with separation scheme. -Isolate the elements in water.

Ethanol Water Charcoal Sucrose (Sugar) Sand

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Elements and Compounds Elements, the Lego for compounds

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Compounds Pure substances made from two or more elements H2O Water NaCl Table Salt C12H22O11 Sucrose C2H5OH Ethanol S8 Sulfur CaCO3 Chalk C8H18 Octane

Compound has unique properties which distinguish it from other chemicals

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Mixtures Combinations of two or more substances

Soda Sucrose/Water/CO2 Salt Water NaCl/H2O Rock SiO2, CaCO3 Beer Ethanol/Water Rubber Sulfur/CnHxn Sand granite, SiO2, chalk Gasoline CnHxn

Mixtures can either be uniform throughout (Homogeneous) or non-uniform throughout (Heterogeneous)

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Inherent differences - At the molecular level what is the difference between the class of matter ?

Need to distinguish difference via observable properties

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Observing the Properties -

What are the properties of matter? Property - that which can be observe or measured.

Property Classification - Matter can be classified into two type of property. Intensive Extensive Temperature Mass Color Volume Density heat B.pt Length phase Area Intensive- Extensive- Independent of size Dependent of size

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Change of States: Phases Consider the following:

solid-liquid-gas How does this take place ? What type of changes are occurring? Is this process reversible ?

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Kinetic Molecular Model - Change of state at the molecular level

Solid - fix neighbors, no translation motion and large attraction between particles. Vibration motion is dominant.

Liquid - random tumbling, large translation but particles still attract each other.

Gas - no attraction for each other and large translation in space.

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Change of Matter Physical change: Identity Retained

Change in the observable properties without change of substance identity:

Refers to material changing form but not identity. Example: Phase Change Physical change of matter in which the identity of the substance is retained.

Chemical change: Identity Changed Refers to material changing to a completely different

type of material, or transformation to a new substance.

This process involves bond breaking and bond forming such that material changes identity.

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Δ Physical Vs. Δ Chemical Sugar dissolving Cutting wood Applying glue Melting ice Breaking glass

Heating Sugar Burning wood Nylon synthesis Electrolysis of water Doping glass

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Separating Matter to its components Exploitation of the different properties of a mixture to separate matter.

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Separating Matter using Physical Techniques

Separation Scheme: Given iodine, sand and CoCl2, what is the best method of separation? The scheme shows sublimation of iodine followed by solubility of CoCl2 and then decanting the sand. The CoCl2 is recovered by evaporating the water.

A, B , C

A separated

B separated

C separated

Similarly, separation of sand, charcoal, sugar, ethanol and water is easily accomplished if the correct physical property of each substance is exploited so that the mixture can be isolated individually.

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Lab Separation Technique: Relation to physical property Separation of a mixture of matter can only be achieve by taking advantage of each substance different physical properties.

Technique Property to be exploited Chromatography Polarity

Distillation Boiling point and Volatility

Filtration Solubility and density

Decant Density

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Summary The Universe = Matter + Energy Matter = Mixture, compounds and elements. • Mixture can be separated to pure substances by

physical means. • Compounds can be separated to elements by chemical

means only. • When separating mixtures by physical means, the

unique properties of matter is used as the basis of separation.