Fundamentals of General, Organic, and Biochemistry Fifth Edition by McMurry, Castellion, and Ballantine

Chemistry: The study of matter and the changes it undergoes. Define matter What is meant here by change?

Three States of Matter Solid: rigid - fixed volume and shape Solid: rigid - fixed volume and shape Liquid: definite volume but assumes the shape of its container Liquid: definite volume but assumes the shape of its container Gas: no fixed volume or shape - assumes the shape of its container Gas: no fixed volume or shape - assumes the shape of its container Link to Video Link to Video Link to Video Link to Video

Check Appearance A homogeneous mixture called a solution looks like pure substances which are also homogeneous A homogeneous mixture called a solution looks like pure substances which are also homogeneous A heterogeneous mixture is, to the naked eye, clearly not uniform A heterogeneous mixture is, to the naked eye, clearly not uniform

Pure Substances Can be isolated from mixtures by separation methods: Can be isolated from mixtures by separation methods: Chromatography Chromatography Chromatography Filtration Filtration Distillation Distillation Recrystalization Recrystalization

Pure Substances Pure substances have specific unchanging physical and chemical properties. Pure substances have specific unchanging physical and chemical properties. Percent by mass of each element Percent by mass of each element Melting points, Boiling points Melting points, Boiling points Density at specified temperature Density at specified temperature Many other properties Many other properties

Element: A substance that cannot be decomposed into simpler substances by chemical means. Compound: A substance with a constant composition that can be broken down into elements by chemical processes.

Classification of Matter

Changes in Matter Physical Changes are changes to matter that do not result in a change in the fundamental components that make that substance State Changes – boiling, melting, condensing If you are talking about a specific substance we call it a Physical Property of that substance.

Changes in Matter Chemical Changes involve a change in the fundamental components of the substance Produce a new substance Specific substance = Chemical Property

Classify Each of the following as Physical or Chemical Changes ¬ Iron is melted. Physical change – describes a state change, but the material is still iron. Iron combines with oxygen to form rust.. Chemical Property of Iron – describes how iron and oxygen react to make a new substance, rust ® Sugar ferments to form ethyl alcohol. Chemical change – describes how sugar becomes a new substance

Chemistry: What do you know? What do you think? What do you believe?

Semester Key Idea Knowing vs. Thinking

Observation Qualitative and Quantitative

Hypothesis Explains an observation. May be changed as soon as new information comes available. Must be testable.

Experimentation Checking your hypothesis by testing the “what if”

Steps in the Scientific Method 1.Observations quantitativequalitative 2.Formulating hypotheses possible explanation for the observation 3.Performing experiments gathering new information to decide whether the hypothesis is valid

Outcomes Over the Long-Term Theory (Model) A set of tested hypotheses that give an overall explanation of some natural phenomenon. overall explanation of some natural phenomenon. Natural Law The same observation applies to many different systems different systems Example - Law of Conservation of Mass

Law vs. Theory A law summarizes what happens. A theory is an attempt to explain why something happens.

The various parts of the scientific method. Note that The Law comes from the observations of the many experiments and does not attempt to explain the observations. The theory explains the observations.