9/25/2018 Principles of Chemistry Chapter 1 Introduction to Chemistry Dr. Hasmerya Maarof Department of chemistry Faculty of Science, UTM What Is Science? • Science is a development of knowledge which study the properties of everything appeared/observed in universe. • Science is just exploring nature. • A scientists is just a person exploring • The science knowledge develops stepwise based on direct or indirect observation through experimental work. Principles of Chemistry 1 9/25/2018 Role of Scientist • As a scientist ✓Must be curious ✓Try to explain with nature observed ✓Communicate and debate ideas with other scientists/people. ✓The Truth is revealed through experimentation – Scientist is not a philosopher Principles of Chemistry Chemistry is • central to modern science, and to almost all • • • • human endeavors. important to all sciences - biology, geology, physics, engineers, etc. a natural science. a language with its own vocabulary. a way of thinking. Principles of Chemistry 2 9/25/2018 What is Chemistry • Pure Chemistry: gathers knowledge for the sake of knowledge • Applied Chemistry: using chemistry to attain certain goals, in fields like medicine, agriculture and manufacturing – leads to an application • Nylon • Aspirin – relieve pain • Detergent Principles of Chemistry What Is Chemistry? • Observation: is sand different than water • Test the similarities and differences between sand and water. ✓Composition ➢Types & number of atoms, structure, ✓Properties ➢Chemical: how hot, how fast ➢Physical: size, ability to loose/gain electrons Principles of Chemistry 3 9/25/2018 What Is Chemistry? • Chemistry is the study of the composition of matter (anything with mass and occupies space), its composition, properties, and the changes it undergoes ✓Example: Burning of fuel C2H5OH + 3O2 2CO2 + 3H2O + energy Principles of Chemistry Structure Determines Properties • Everything is made of tiny particles called atoms and molecules. • Chemists study these particles, looking at the kinds, numbers, structure, size which produce varying chemical and physical properties. Principles of Chemistry 4 9/25/2018 5 Major Areas of Chemistry • Analytical Chemistry: concerned with the composition of substances • Inorganic Chemistry: deals with substances without carbon • Organic Chemistry: essentially all with substances containing carbon • Physical Chemistry: describes the behaviour of chemicals • Biochemistry: chemistry of living things substances Principles of Chemistry 1. Organic Chemistry • Organic is the study of matter that contains carbon • Organic chemists study the structure, function, synthesis, and identity of carbon compounds • Useful in petroleum industry, pharmaceuticals, polymers 5 9/25/2018 2. Inorganic Chemistry • Inorganic is the study of matter that does NOT contain carbon • Inorganic chemists study the structure, function, synthesis, and identity of non-carbon compounds • Polymers, Metallurgy 3. Biochemistry • Biochemistry is the study of chemistry in living things • Cross between biology and chemistry • Pharmaceuticals and genetics 6 9/25/2018 4. Physical Chemistry • Physical chemistry is the physics of chemistry… the forces of matter • Much of p-chem is computational • Develop theoretical ideas for new compounds 5. Analytical Chemistry • Analytical • • chemistry is the study of high precision measurement Find composition and identity of chemicals Forensics, quality control, medical tests 7 9/25/2018 Activity 1.1 • Why study Chemistry? ✓Journey where we explore nature ✓Loves research around her (curiosity) – how to do ice-cream, perfume ✓Like chemistry subject (passion) ✓Love sharing knowledge – lecturer to be ✓Score the most in chemistry subject – Pakar kimia ✓Fav subject, kesian dgn cikgu sebab kawan tak suka subjek ni Introductory Chemistry 8 9/25/2018 Activity 1.2 • Why Chemistry is important any aspects in life? ✓Everything in our life need explanation and chemistry can explain all ✓Knowledge chemistry sentiasa berkembang ✓Can create new things by chemistry knowledge ✓Apply knowledge to solve chemical problem Introductory Chemistry Why Study Chemistry? • Everyone and everything around us involves chemistry – explains our world • Make the world a better place • New materials to fit specific needs ✓Perfume, steel, ceramics, plastics, rubber, paints, non-stick cooking utensils, polyester • Sources of energy ✓Fossil fuels, solar, batteries, nuclear, hydrogen Principles of Chemistry 9 9/25/2018 Why Study Chemistry? • Medicine and Biotechnology ✓Medicine and material for treating patients vitamin C, penicillin, aspirin ✓Bacteria producing insulin ✓cloning • Agriculture ✓World’s food supply, better productivity, plant growth hormones, ways to protect crops Principles of Chemistry Why Study Chemistry? • Environment ✓ Pollution, global warming • Astronomy and Space Exploration✓composition of the planets ✓analyze moon rocks ✓planet atmospheres ✓life on other planets? Principles of Chemistry 10 9/25/2018 The Scientific Method • Humans are by nature curious. • Have you ever heard a 3-year old repeatedly ask • “why?” Science is just exploring nature. • Chemistry – alchemy, medicine, technology ✓Practical - technique ✓Mystical - Concepts Principles of Chemistry The Scientific Method • 1500s – a shift from alchemy to science • Scientists encouraged to use more experimental evidence and not philosophical debates • Lavoisier – transformed chemistry from science of observation to the science of measurement ➢Long debate about burning – Oxygen was required!!! Principles of Chemistry 11 9/25/2018 The Scientific Method • A logical approach to solving problems or answering questions • You begin to organize your thoughts into Observation, you group those observations into Hypotheses, using Experimentation, and formulate Laws or Theories. Principles of Chemistry Observation • Acquiring information or data • Some observations are simple descriptions ✓ “The soda pop is a liquid with a brown color and a sweet taste. Bubbles are seen floating up through it.” • Some observations compare a characteristic. ✓ “A 240-mL serving of soda pop contains 27 g of sugar.” Principles of Chemistry 12 9/25/2018 Hypothesis • Looking at your observations: ✓The sweetness of soda pop is due to the presence of ➢Sugar or ➢Aluminum • Formulating hypothesis (ideas) ✓Possible explanation for observation, or educated guess to the cause of the problem Principles of Chemistry Experiments • Test your hypotheses with a taste test: sugar and • aluminum. Controlled experiment – designed to test hypothesis (right or wrong) Modify hypothesis – repeat cycle • • Variables – factors that can change ➢Manipulated (independent variable) – one that we change ➢Responding (dependent variable) – observed during experiment Principles of Chemistry 13 9/25/2018 Theory • Results to be accepted, experiment needs to always produce the same results ➢Sugar is sweet • Theory – A set of well-tested hypotheses that give an overall explanation of some natural phenomenon or why things behave a certain way. Principles of Chemistry Laws • Typically a fact of nature, often a math constant/number and unit. ✓Law of Conservation of Mass— “In a chemical reaction matter is neither created nor destroyed.” ✓Speed of Light, E = mc2, Dalton’s Gas Law, Universal Gas Constant, etc… • Unlike Malaysian laws, you cannot choose to violate a scientific law ☺ Introductory Chemistry 14 9/25/2018 Using your senses to obtain information The procedure that is used to test the hypothesis Hypothesis is a proposed explanation; should be based on previous knowledge; an “educated” guess A well-tested explanation for the observations; cannot be proven due to new discoveries Tells what happened Theories • Explains how nature behaves. ✓Newton’s Gravitational Theory ✓Dalton’s Atomic Theory: ✓Darwin’s Theory of Evolution ✓Einstein's Theory of Relativity • Used to predict future observations. Introductory Chemistry 15 9/25/2018 What’s the Difference Between a Law and a Theory? • Laws: Very specific, “What will happen” • often expressed in mathematical equations. Theories: Very general, “Why it will happen,” often includes many “Laws” Introductory Chemistry Observations Hypothesis Theory (Model) Modify Experiment Prediction Law Experiment 16 9/25/2018 How to succeed in Chemistry? • • • • • • • Don’t give up Passion Rajin buat experiment Sabar, patient Curious Read & understand Sharing & discuss Introductory Chemistry How to Succeed in Chemistry • Curiosity and your imagination are your allies ✓Explore and investigate. • Quantify and calculate ✓Even small differences can be important! • Commitment ✓Work regularly and carefully. Introductory Chemistry 17 9/25/2018 The Best Approach to Learning Chemistry • Learn the vocabulary of chemistry. ✓ Definitions and terms. ✓ How common vocabulary is applied to chemistry. • Memorize important information. ✓ Names, formulas, and charges of polyatomic ions. ✓ Solubility rules. • Learn and practice processes. ✓ Systematic names and formulas. ✓ Dimensional analysis. • Do the questions and exercises in the chapter to test your understanding and help you learn the patterns? Introductory Chemistry Problem Solving in Chemistry • Numerical ➢ Analyze • Identify known factors, unknown, units, relate factors and choose an equation (use table or graph and given information) ➢ Calculate • Perform the mathematics, use calculator ➢ correctly, rearrange equation, conversion of units Evaluate Introductory Chemistry 18 9/25/2018 Problem Solving in Chemistry • Conceptual problem ➢ Analyze • Identify and link known factors to unknown • No calculations ➢ Solve Introductory Chemistry 19