Chemistry - Chp 1 - Introduction To Chemistry - PowerPoint
Chapter 1“Introduction to Chemistry”
Section 1.1 Chemistry OBJECTIVES: –Identify five traditional areas of study in chemistry. –Relate pure chemistry to applied chemistry. –Identify reasons to study chemistry.
What is Chemistry? Chemistry is the study of the composition of “matter” its composition, properties, and the changes it undergoes. Matter - anything with mass and occupies space Chemistry has a definite affect on everyday life - taste of foods, grades of gasoline, etc. Living and nonliving things are made of matter.
Chemistry is the study of the composition, structure, and properties of matter and the changes it undergoes – such as burning fuels.C2H5OH + 3 O2 2 CO2 + 3 H2O + Energy Reactants Products
5 Major Areas of Chemistry1) Analytical Chemistry- concerned with the composition of substances.2) Inorganic Chemistry- primarily deals with substances without carbon3) Organic Chemistry- essentially all substances containing carbon4) Biochemistry- Chemistry of living things5) Physical Chemistry- describes the behavior of chemicals (ex. stretching); involves lots of math!Boundaries not firm – they overlap and interact
What is Chemistry? Pure chemistry- gathers knowledge for the sake of knowledge Applied Chemistry- is using chemistry to attain certain goals, in fields like medicine, agriculture, and manufacturing – leads to an application * Nylon * Aspirin (C9H8O4) * Use of TECHNOLOGY
Why Study Chemistry? Everyone and everything around us involves chemistry – explains our world What in the world isn’t Chemistry? Helps you make choices; helps make you a better informed citizen A possible career for your future Used to attain a specific goal
Why Study Chemistry? With a partner… –Give examples in your daily life that involve use of chemistry, and things that do not?
Section 1.2 Chemistry Far and Wide OBJECTIVES: –Identify some areas of research affected by chemistry. –Describe some examples of research in chemistry.
Section 1.2 Chemistry Far and Wide OBJECTIVES: –Distinguish between macroscopic and microscopic views.
Chemistry Far and Wide Chemists design materials to fit specific needs Ex.) velcro, perfume, steel, ceramics, plastics, rubber, paints, nonstick cooking utensils, polyester fibers Two different ways to look at the world:1. Macroscopic2. Microscopic
Chemistry Far and Wide Energy – we constantly have greater demands Q: How can we meet these demands? A: Conserve it or use it wisely Ex.) fossil fuels, solar, wind, batteries (that store energy – or rechargeable), nuclear
Chemistry Far and Wide Medicineand Biotechnology- –Supply materials doctors use to treat patients –vitamin C, penicillin, aspirin (C H O ) 9 8 4 –materials for artery transplants and hipbones –bacteria producing insulin
Chemistry Far and Wide Norman BorlaugAgriculture Nobel Peace Prize Presidential Medal of freedom Congressional Gold Medal Father of the Green Revolution Credited with saving over 1 billion people from starvation
Chemistry Far and Wide Agriculture – increase the world’s food supply – Use chemistry for better productivity – soil, water, weeds – plant growth hormones – ways to protect crops; insecticides – disease resistant plants
Chemistry Far and Wide The Environment – both risks and benefits involved in discoveries – Pollutants need to be – 1) identified and 2) prevented – Lead paint was prohibited in 1978; Leaded gasoline? Drinking water? – carbon dioxide, ozone
- Page 16 Let’s examine some information from a graph. 88.2%440,000 After lead was banned in gasoline and public water supply systems, less lead entered the environment.
Chemistry Far and Wide The Universe –Need to gather data from afar, and analyze matter brought back to Earth –composition of the planets –analyze moon rocks –planet atmospheres –life on other planets?
Section 1.3 Thinking Like a Scientist OBJECTIVES: –Describe how Lavoisier transformed chemistry. –Identify three steps in the scientific method.
Section 1.3 Thinking Like a Scientist OBJECTIVES: –Explain why collaboration and communication are important in science.
Alchemy – developed the tools and techniques for working with chemicals The word chemistry comes from alchemy – practiced in China and India since 400 B.C. Alchemy has two sides: – Practical: techniques for working with metals, glass, dyes, etc. – Mystical: concepts like perfection – gold was a perfect metal
An Experimental Approach In the 1500s, a shift started from alchemy to science – King Charles II was a supporter of the sciences “Royal Society of London for the Promotion of Natural Knowledge” Encouraged scientists to use more experimental evidence, and not philosophical debates
Lavoisier Inthe late 1700s, Antoine Lavoisier helped transform chemistry from a science of observation to the science of measurement – still used today He settled a long-standing debate about burning, which was… –Oxygen was required!
The Scientific MethodA logical approach to solving problems or answering questions. Starts with observation- noting and recording information and facts hypothesis- a proposed explanation for the observation; must be tested by an experiment
Steps in the Scientific Method1. Observations (uses your senses) a) quantitative involves numbers = 95oF b) qualitative is word description = hot2. Formulating hypotheses (ideas) - possible explanation for the observation, or “educated” guess3. Performing experiments (the test) - gathers new information to help decide whether the hypothesis is valid
Scientific Method “controlled” experiment- designed to test the hypothesis only two possible answers: 1) hypothesis is right 2) hypothesis is wrong We gather data and observations by doing the experiment Modify hypothesis - repeat the cycle
Scientific Method We deal with variables, or factors that can change. Two types: 1) Manipulated variable (or independent variable) is the one that we change 2) Responding variable (or dependent variable) is the one observed during the experiment For results to be accepted, the experiment needs to always produce the same result
Outcomes over the long term… Theory (Model) - A set of well-tested hypotheses that give an overall explanation of some natural phenomenon – not able to be proved Natural Law (or Scientific Law) - The same observation applies to many different systems; summarizes results - an example would be: the Law of Conservation of Mass
Law vs. TheoryA law summarizes what has happened.A theory (model) is an attempt to explain why it happened – this changes as new information is gathered.
- Page 22Using your senses to The procedure that is usedobtain information to test the hypothesisHypothesis is a Tells what happenedproposed explanation;should be based on A well-tested explanation forprevious knowledge; an the observations; cannot be“educated” guess proven due to new discoveries
Collaboration / Communication When scientists share ideas by collaboration and communication, they increase the likelihood of a successful outcome How is communication done? Is the Internet reliable information? – http://www.dhmo.org
Section 1.4 Problem Solving in Chemistry OBJECTIVES: –Identify two general steps in problem solving. –Describe three steps for solving numeric problems. –Describe two steps for solving conceptual problems.
Problem Solving in Chemistry We are faced with problems each day, and not just in chemistry A solution (answer) needs to be found Trial and Error may work sometimes? But,there is a method to problem solving that works better, and these are skills that no one is born knowing – they need to be learned.
Problem Solving in Chemistry Effective problem solving usually involves two general steps: 1) Developing a plan 2) Implementing that plan The skills you use to solve a word problem in chemistry are NOT different from those techniques used in shopping, cooking, or planning a party.
Solving Numeric Problems Measurements are an important part of chemistry; thus many of our word problems involve use of mathematics – Word problems are real life problems, and sometimes more information is presented than needed for a solution Following skills presented will help you become more successful
Solving Numeric Problems The three steps we will use for solving a numeric word problem are: 1) Analyze Let’s learn how to ACE these 2) Calculate numeric word 3) Evaluate problems! The following slides tell the meaning of these three steps in detail.
Solving Numeric Problems1) Analyze: this is the starting point – Determine what are the known factors, and write them down on your paper! – Determine what is the unknown. If it is a number, determine the units needed – Plan how to relate these factors- choose an equation; use table or graph This is the heart of successful problem solving techniques – it is the PLAN
Solving Numeric Problems2) Calculate: perform the mathematics – If your plan is correct, this is the easiest step. – Calculator used? Do it correctly! – May involve rearranging an equation algebraically; or, doing some conversion of units to some other units.
Solving Numeric Problems3) Evaluate: – the finishing step – Is it reasonable? Make sense? Do an estimate for the answer, and check your calculations. – Need to round off the answer? – Do you need scientific notation? – Do you have the correct units? – Did you answer the question?
Solving Conceptual Problems Not all word problems in chemistry involve doing calculations Nonnumeric problems are called conceptual problems – ask you to apply concepts to a new situation Steps are: 1) Analyze and 2) Solve Plan needed to link known to unknown, but no checking units or calculations Do Conceptual Problem 2.1 on page 46