Chapter 1 - Introduction to Chemistry

Objectives Define Chemistry Differentiate between the 5 branches of Chemistry Apply the general plan in solving chemistry word problems

SECTIONS 1.1 Chemistry 1.2 Chemistry Far and Wide 1.3 Thinking Like a Scientist 1.4 Problem Solving in Chemistry

1.1 Chemistry Matter – anything that takes up space and has mass Chemistry – the study of matter and the changes that matter undergoes Organic Chemistry – the study of all chemicals that contain carbon Inorganic Chemistry – the study of chemical that do not contain carbon Biochemistry – the study of processes that take place in organisms Analytical Chemistry – the study of composition of matter Physical Chemistry – the area that deals with the mechanism, the rate and the energy transfer that occurs when matter undergoes a change Pure Chemistry - the pursuit of chemical knowledge for its own sake Applied Chemistry – research that is directed toward a practical goal or application Technology – a system of tools, mechanisms, methods to solve a problem, improve a problem or change a problem Vocabulary - Matter - Chemistry - Organic chemistry - Inorganic Chemistry - Biochemistry - Analytical Chemistry - Physical Chemistry - Pure Chemistry - Applied Chemistry - Technology Video – What is Chemistry?

Branches of Chemistry Inorganic Organic Analytical Physical Biochemistry

Identify some of the components of this picture and match it with one of the Chemistry branches

Mass vs Weight Mass: a measure of the amount of matter that an object contains. (SI unit kilogram, kg) Weight: The force with which the earth pulls on an object. (SI unit Newton, N)

Organic or Inorganic ? Sulfuric Acid H 2 SO 4 Methane CH 4 Hydrochloric Acid HCl EthaneC 2 H 6

Science What? Why? How? When?

Science and Technology Science  Pure Does not necessarily have an application. Technology  Applied Has practical applications in society. Engineering.

1.2 Chemistry Far and Wide Macroscopic – objects are seen without a microscope Microscopic - objects that cannot be seen without microscope Biotechnology – an applied science that uses techniques to produce or process different things Pollutant - a material found in air, soil or water that hurts living things Vocabulary - Macroscopic - Microscopic - Biotechnology - Pollutant

Energy is the ability to do work.

Nature of Energy Energy is involved when: a bird flies. a bomb explodes. rain falls from the sky. electricity flows in a wire.

Production of Energy Hydroelectric plants use running water to generate electricity, however they may flood nearby lands and can disrupt the normal flow of water, both of which negatively affect the environment.

Wind power is increasingly being used as a clean source of renewable energy. Turbines harvest wind on wind farms and generate electricity.

Solar power is a promising, renewable energy resource than can be turned into electricity, and it is used in many toys and even home heating.

Many other alternative energy sources like geothermal power, which draws upon the earth’s natural heat, and biomass, which produces an alternative to gasoline, are being considered in the movement away from fossil fuel dependence.

Conservation of Energy In our everyday lives, we can also work to conserve energy. Insulating, turning off lights and only using appliances like dishwashers when they are full are just some of the ways people can limit energy use in their homes. Also, carpooling, bicycling, and taking public transportation are effective energy-saving ideas.

What is Biotechnology? Biotechnology is the manipulation of living organisms and organic material to serve human needs. Examples: Yeast in bread making and alcohol production Use of beneficial bacteria (penicillin) to kill harmful organisms Cloning of plants and animals Artificial insemination

1750 B.C. Origins of “biotechnology” emerge in methods of food production and plant and animal breeding Use of bacteria to produce cheese (food preservation) Use of natural enzymes in yogurt Use of yeast to produce bread Use of fermentation for producing wine and beer

Biotechnology Industry Focuses on a variety of research areas including: Health/medicine Food science Environmental science Agriscience

1.3 Thinking Like a Scientist Scientific Method - a logical approach to the solution of a scientific problem Observation – the use of senses to obtain an information Hypothesis – an educated guess Experiment – a procedure used to verify the hypothesis Manipulated variable – the variable that you change during an experiment Responding variable – the variable that is observed during the experiment Theory - a well tested explanation for a broad set of observations Scientific Law – a concise statement that summarizes the results of many observations and experiments Vocabulary - Scientific Method - Observation - Hypothesis - Experiment - Manipulated variable - Responding variable - Theory - Scientific law

Steps of the Scientific Method Problem/Question 1. Problem/Question: Develop a question or problem that can be solved through experimentation.

Steps of the Scientific Method Formulate a Hypothesis 3. Formulate a Hypothesis: Predict a possible answer to the problem or question. Example: If soil temperatures rise, then plant growth will increase.

Steps of the Scientific Method Experiment 4. Experiment: Develop and follow a procedure. Include a detailed materials list. The outcome must be measurable (quantifiable).

Steps of the Scientific Method Collect and Analyze Results 5. Collect and Analyze Results: Modify the procedure if needed. Confirm the results by retesting. Include tables, graphs, and photographs.

Steps of the Scientific Method Conclusion 6. Conclusion: Include a statement that accepts or rejects the hypothesis. Make recommendations for further study and possible improvements to the procedure.

Steps of the Scientific Method Communicate the Results 7. Communicate the Results: Be prepared to present the project to an audience. Expect questions from the audience.

Problem/Question John wonders if the amount of sugar used in the recipe will affect the size of the bread loaf?

Caution! Be careful how you use effect and affect. Effect is usually a noun and affect, a verb. “ The effect of sugar amounts on the rising of bread.” “How does sugar affect the rising of bread?”

Observation/Research John researches the areas of baking and fermentation and tries to come up with a way to test his question. He keeps all of his information on this topic in a journal.

John talks with his teacher and she gives him an Experimental Design Diagram to help him set up his investigation.

Formulate a Hypothesis After talking with his teacher and conducting further research, he comes up with a hypothesis. “If more sugar is added, then the bread will rise higher.”

Hypothesis The hypothesis is an educated guess about the relationship between the independent and dependent variables. Note: These variables will be defined in the next few slides.

Independent Variable The independent, or manipulated variable, is a factor that’s intentionally varied by the experimenter. John is going to use 25g., 50g., 100g., 250g., 500g. of sugar in his experiment.

Dependent Variable The dependent, or responding variable, is the factor that may change as a result of changes made in the independent variable. In this case, it would be the size of the loaf of bread.

Experiment His teacher helps him come up with a procedure and list of needed materials. She discusses with John how to determine the control group.

Control Group In a scientific experiment, the control is the group that serves as the standard of comparison. The control group may be a “no treatment" or an “experimenter selected” group.

Control Group The control group is exposed to the same conditions as the experimental group, except for the variable being tested. All experiments should have a control group.

Control Group Because his grandmother always used 50g. of sugar in her recipe, John is going to use that amount in his control group.

Constants John’s teacher reminds him to keep all other factors the same so that any observed changes in the bread can be attributed to the variation in the amount of sugar.

Constants The constants in an experiment are all the factors that the experimenter attempts to keep the same.

Constants They might include: Other ingredients to the bread recipe, oven used, rise time, brand of ingredients, cooking time, type of pan used, air temperature and humidity where the bread was rising, oven temperature, age of the yeast…

Experiment John writes out his procedure for his experiment along with a materials list in his journal. He has both of these checked by his teacher where she checks for any safety concerns.

Trials Trials refer to replicate groups that are exposed to the same conditions in an experiment. John is going to test each sugar variable 3 times.

Collect and Analyze Results John comes up with a table he can use to record his data. John gets all his materials together and carries out his experiment.

Size of Baked Bread (LxWxH) cm 3 Amt. of Sugar (g.) 123Average Size (cm 3 ) Size of Bread Loaf (cm 3 ) Trials Control group

Collect and Analyze Results John examines his data and notices that his control worked the best in this experiment, but not significantly better than 100g. of sugar.

Conclusion John rejects his hypothesis, but decides to re-test using sugar amounts between 50g. and 100g.

Experiment Once again, John gathers his materials and carries out his experiment. Here are the results.

Can you tell which group did the best? Can you tell which group did the best?

Size of Baked Bread (LxWxH) cm 3 Amt. of Sugar (g.) 123Average Size (cm 3 ) Size of Bread Loaf (cm 3 ) Trials Control group

Conclusion John finds that 70g. of sugar produces the largest loaf. His hypothesis is accepted.

Communicate the Results John tells his grandmother about his findings and prepares to present his project in Science class.

Producing aspirin tablets so that consumers can use them. Question: Science or Technology?

Alchemists (~300BC-1650 AD) China, India, Arabia, Europe, Egypt Aiming to:  Change common metals to gold.  Develop medicines. Developed lab equipment. Mystical.

Question: Does an iron nail gain mass or lose mass when it rusts (a form of burning)?

Theory A well tested explanation for a broad set of observations. May use models. May allow predictions. Theories may change to explain new observations.

Law A statement that summarizes results of observations, but does not explain them. Changes or is abandoned when contradicted by new experiments.

Note: The order of the steps can vary and additional steps may be added.

“ No number of experiments can prove me right; a single experiment can prove me wrong.” Albert Einstein

Why Study Chemistry - 3 Main Reasons 1.) Understand the Natural World 2.) Career Preparation 3.) Becoming an informed citizen

Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. Why Study Chemistry? Explaining the Natural World  why cut apples turn brown upon exposure to air.  why the texture of eggs changes from runny to firm as eggs are boiled.  why water expands as it freezes.  why sugar dissolves faster in hot water than in cold water.  why yeast makes bread dough rise. Satisfy your curiosity…

Why Study Chemistry? Preparing for a Career Doctor Nursing Firefighter Turf Management Geothermal Specialist Engineering Artist Chef Mechanic Painters Farmer Law Enforcement Professional Hunter Physical Therapist Copyright © Pearson Education, Inc., or its affiliates. All Rights Reserved. You do not need to have the word chemist in your job title to benefit from understanding chemistry.

Assignments Watch the PPT at least 2 times or read the textbook; - Understand and memorize the definitions of all key terms; Write in your notebook (homework section) the key terms and their definitions and some notes that you consider will help with the “do now” and they will meet the objectives Solve for yourself all the questions and problems given by the textbook at the end of each section.

Assignments Watch the PPT at least 2 times or read the textbook; Understand and memorize the definitions of all key terms; Write in your notebook (homework section) the key terms and their definitions and some notes that you consider will help with the “do now” and they will meet the objectives Solve for yourself all the questions and problems given by the textbook at the end of each section.

Assignments Homework check list: Date written on upper right corner; Title containing homework number, chapter number and the name of the chapter.