Chemistry- Matter and change HONORS CHEMISTRY CHAPTERS 1 + 2

The study of the composition and changes undergone by matter CHEMISTRY DEFINED Physiology Forensics Chemistry GeosciencesPhysics Biology Environmental Science

FIVE BRANCHES OF CHEMISTRY  Organic  Inorganic  Analytical- composition of substances.  Physical-behavior of chemical substances  Biochemistry

 Pure  For the advancement of knowledge about our world  Many “Pure” pursuits lead to practical applications (i.e. nylon)  Applied  For a specific issue that faces society  Pharmaceuticals, etc. CHEMISTRY CAN BE… Read “The Symbiosis of Pure and Applied Science” posted under the Introduction to Chemistry topic and respond to the discussion question

SCIENTIFIC METHOD Observation Hypothesis Law Theory Experiment

IMPORTANT DISTINCTION Arise following many, many experiments

 Independent Variable – manipulated variable  Dependent Variable – responding variable  Qualitative- sensory observations (EX: brown)  Quantitative- numerical measurements (EX: 5 grams)  Observation- objective explanation of phenomena  Inference- subjective explanation of phenomena IMPORTANT DISTINCTIONS CONTINUED

STATES OF MATTER  Matter CAN change state  Three basic states of matter SOLIDLIQUIDGAS Definite Shape Definite Volume Particle Spacing

 Properties that can be observed without changing the composition of matter. PHYSICAL PROPERTIES OF MATTER Anything that has mass * and takes up space A measurement that reflects the amount of matter Extensive properties are dependent on the amount of matter present Intensive properties are independent of the amount of matter present. *not to be confused with weight

CLASSIFICATION OF MATTER *Phase refers to any part of a sample with uniform composition

 ALL MIXTURES CAN BE SEPERATED PHYSICALLY by exploiting the physical properties of the components  Filtration- used to separate a mixture with widely varying particle size  EX: rocks and water  Distillation- used to separate a liquid mixture based on differing boiling points.  EX: alcohol and water  Crystallization- used to separate an aqueous mixture  EX: salt water  Chromatography- separates a mixture based on polarity (affinity for stationary/mobile phase) SEPARATING MIXTURES

DISTILLATION 1.Substance with the lowest boiling point will vaporize first. 2.Vapor will condense to a liquid as it flows through the condenser. 3.Liquid (distillate) can be collected.

CLASSIFICATION OF MATTER

CHANGES TO MATTER  Physical change- occurs without altering makeup  Chemical change- occurs through alteration of substance

 Must involve at least one material changing into a new material and  Must obey the Law of Conservation of Mass:  Mass is neither created nor destroyed in chemical reaction CHEMICAL REACTIONS

INDICATIONS OF A CHEMICAL CHANGE Change in color Change in temperature Formation of a precipitate Formation of a gas