Chemistry 139 General Chemistry Prep Your Instructor is

Chemistry& 139 General Chemistry Prep Your Instructor is Dr Lee West Welcome !!

First of all lets get the formalities out of the way…. Instructor: Lee West Office: LSC-114 Phone: (253) 864 -3353 Email: lwest@pierce. ctc. edu Office Hours: Mon-Thurs 12 PM – 1: 30 PM

Class Times: Tues and Thur 2: 15 PM - 4: 25 PM (LSC-244) Textbook: “Introduction to Chemical Principles” (11 th edition) by H. S. Stoker. Calculator: Students must have a basic scientific, calculator. Bring calculator and book to each class

Quizzes: Short quizzes will be given in class on Thursdays when no test is scheduled. No makeup quizzes will be given, but the lowest quiz score will be dropped.

Homework: Will be given daily. Homework will be peer evaluated in the first ten minutes of each class.

Tests: Three tests will be given. Final Exam: The final exam is comprehensive and will cover all material presented during the quarter.

The Science of Chemistry 1. 1 Chemistry - A Scientific Discipline 1. 2 Scientific Research and Technology 1. 3 The Scope of Chemistry 1. 4 How Chemists Discover Things – The Scientific Method 1. 5 Limitations of the Scientific Method 1. 6 Application Limits for methods of Science

The Science of Chemistry 1. 1 Chemistry - A Scientific Discipline

What is Chemistry? Boring…. Difficult… The object of my hatred…. The stupid class I have to repeat…. Chemistry can be defined as: “The scientific discipline concerned with the study of matter its properties and transformations”

What is science? What does Wikipedia say? “is a systematic enterprise that builds and organizes knowledge in the form of testable explanations and predictions about nature and the universe. ”

Science can be more simply defined as: “An approach to the study of The Universe” In science an assumption is made that: “The Universe obeys laws of natural origin” The role of a scientist is to: “identify and understand these laws using the scientific method”

Chemistry is a scientific discipline. What is a scientific discipline? “A branch of science limited in scope and size to make it more manageable” A lot of overlap between disciplines!

Chemistry can de divided further into sub-disciplines The American Chemical Society (ACS) has 33 subdivisions! (Table 1. 1 page 3)

The Science of Chemistry 1. 1 Chemistry - A Scientific Discipline Science is a systematic approach to the study of the universe based on observation and experiment. Chemistry is a subdivision of science. Chemistry is a physical science concerned with the study of matter and energy. Chemistry can be divided into a wide array of subdivisions focusing on differing topics. This course will focus on general chemistry which seeks to understand the fundamental laws and concepts of chemistry.

The Science of Chemistry 1. 2 Scientific Research and Technology

In science new knowledge is obtained through the process of scientific research. Scientific research can be defined as: “the systematic investigation into a subject” Scientific research is often divided into two broad categories: § Basic research, concerned with discovery of fundamental information § Applied research, concerned with the discovery of new products and processes

The information discovered through scientific research is often used to develop new technology. Technology can be defined as: “new products and processes intended to improve the quality of human life” Sometimes technology has unintended (detrimental) outcomes.

The Science of Chemistry 1. 2 Scientific Research and Technology In science new knowledge is obtained by conducting scientific research. Basic scientific research is concerned with obtaining new fundamental information, applied scientific research is concerned with the discovery of new products and processes. Technology is the application of research to produce new products and processes to benefit Humans. Technology can have both detriments and benefits.

The Science of Chemistry 1. 3 The Scope of Chemistry

Earlier we said chemistry can be defined as: “The scientific discipline concerned with the study of matter, its properties and transformations” What is Matter? “The physical material of the universe. ” “Anything that occupies space and has mass”

Mass is the quantity that describes the amount of matter in an object. • The mass of an object is constant at every place in the universe. • Mass is measured using a balance.

Weight of an object describes the force of gravity acting on it and varies with location.

From our definitions of chemistry and matter we can see that the scope of chemistry encompasses an enormous and broad field.

The Science of Chemistry 1. 3 The Scope of Chemistry is concerned with the study of the properties of matter and the changes it undergoes. Matter can be defined as anything that has mass and occupies space. Consequently, the scope of chemistry is very large and impacts almost all aspects of our lives and the world we live in.

The Science of Chemistry 1. 4 How Chemists Discover Things – The Scientific Method

The scientific method is a generalized procedure used to obtain new information to explain natural phenomena. The scientific method incorporates the following key steps: 1. Identify the problem and plan what data needs to be collected to gather information about the problem. 2. Collect data through experiments and observations. 3. Analyze data to identify generalizations that summarize observations. 4. Suggest explanations for observations. 5. Perform further experiments to prove or disprove explanations.

Chemists use experiments to collect information about a system. An experiment can be defined as: “A well-defined, controlled procedure for obtaining information about a system” During the course of an experiment a chemist will make observations (things we see, hear, smell taste, or feel).

The observations made during experiments are called data. Data may be either: § Qualitative data (non-numerical) e. g. color, smell, sound etc. § Quantitative data (numerical) e. g. density, temperature, mass etc. Well designed experiments attempt to study one variable while keeping all others constant. Similarly, well designed experiments are performed under controlled conditions where the values of all variables are known.

A scientific fact is a reproducible piece of data obtained through an experiment. Scientists publish the data from their experiments so that other scientists can critique and double-check their results and experimental design. Data from basic research is most commonly published in peerreviewed journals.

Scientific hypothesis are “testable explanations of scientific laws” Scientific hypothesis are plausible but tentative explanations that can be tested by further experimentation. § Experiments can disprove a hypothesis § Experiments cannot prove a hypothesis Non-scientific disciplines often have a different definition of a hypothesis, often omitting the testability requirement.

Example: Classify each of the following as a scientific fact, scientific law or scientific hypothesis. (a) In an experiment a log was observed to burn with an orange flame scientific fact (b) Burning logs generate heat and light as a result of the reaction between cellulose and oxygen. scientific hypothesis (c) Burning logs generate heat and light scientific law (d) A burning log was observed to generate heat scientific fact

A scientific hypothesis that has been tested and validated over a long period of time is often described as being a scientific theory. Scientific theories are useful as they: § Allow scientists to make predictions about the outcomes of experiments yet to be performed. § Summarize a large number of scientific facts. Many scientific theories have limitations, however, they continue to be useful in many applications.

The Science of Chemistry 1. 4 How Chemists Discover Things – The Scientific Method Chemists investigate natural phenomena using the scientific method. In the scientific method experiments are performed to collect data (scientific facts), natural laws are formulated that summarize the relationships between different scientific facts, scientific hypothesis are proposed that explain the scientific laws, further experiments are conducted to test these hypothesis if after extensive testing the hypothesis is not disproven the scientific hypothesis assumes the status of scientific theory.

The Science of Chemistry 1. 5 Limitations of the Scientific Method

A scientific theory is always considered provisional. At any time a new experiment or more sensitive apparatus may be designed that disproves the currently held theory.

The Science of Chemistry 1. 5 Limitations of the Scientific Method A theory produced by the scientific method can only ever be considered provisional as a unthought-of experiment or new instrumentation may at some time in the future generate data inconsistent with the current theory. However, if many attempts to disprove a theory fail it becomes a generally accepted truth.

The Science of Chemistry 1. 6 Application Limits for methods of Science

The scientific method is designed to explore natural phenomena. e. g. Do objects fall towards the center of the Earth? The scientific method relies heavily on experimentation. Phenomena for which experiments cannot be designed are not amenable to study using the scientific method. e. g. String theory, quantum gravity, religious questions (what is ethical behavior? ), philosophical questions (what is the purpose of life? )

The Science of Chemistry 1. 6 Application Limits for methods of Science The scientific method is limited to studying natural phenomena for which we can design experiments to investigate. Other phenomena are often explored using alternative methodologies e. g. rational argument (philosophy), quantitative and symbolic reasoning (mathematics), divine revelation (religion) etc.