Lecture 1: Introduction to Chemistry General Chemistry - SPRING 2017 Course lecturer : Jasmin Šutković 20.02.2017

Grading criteria Link for the book: Quizzes(2x) 2 x 10% = 20% Midterm exam Homework’s (5x) Project (paper and presentation) 20% 10% Attendance (Required, more than 70%) 5% Final exam 35% Total 100% Link for the book: https://drive.google.com/open?id=0B1lV-EMiZm99dnhSTE9GR09IRWc My IUS account: http://gbe.ius.edu.ba/jasmin-sutkovic

Book

Contents 1. Chemistry in our lives 2. Chemistry and Chemicals International University of Sarajevo 1. Chemistry in our lives 2. Chemistry and Chemicals 3. Scientific Method 4. Key Math Skills for Chemistry Next time: Chemistry and measurement

Why we study Chemistry ?: Chemistry of our lives International University of Sarajevo Why we study Chemistry ?: Chemistry is the study of properties of substances and how they react with one another . It is an experimental science based of the scientific method! Hunderds of materials that we use EVERY DAY , directly and indirectly, are the products of chemical reseacrh. For example: Plastics , Computer Chips, paper, fuels, cement, ceramics, sollar cells, Cosmetics and so on......... WE NEED CHEMISTRY TO UNDERSTAND OUR ENVIRONMENT!!

Important chemistry processess in our life ! Digestion.. Cooking.. When you write with ink on paper..! Steel is 94% iron and 6% carbon. The carbon forms complex bonds making steel so strong that you can bend an iron crowbar, but not a steel one. ANYTHING that burns is undergoing a chemical reaction and almost always creates some form of carbon as waste. Digestion; enzymes promoting chemical reactions that power our bodies. Lifting your arm requires your body to make and burn ATP using oxygen with carbon dioxide as one of the waste gases produced. Cooking is the heating and combination of compounds to make something new. In some cases, like rising bread we have an actual chemical reaction where the yeast changes the food. When you write with ink on paper, the ink and paper unite in a chemical reaction so that you can't erase it. Specialized inks allow a short period where you can erase some inks, but most inks dry and can't be erased; they have bound with the paper. This includes your pen and your ink jet printer. The sun undergoes fusion, and yes that too is chemistry. It creates radiation and photons so we can see. Some of the radiation interacts with oxygen to create ozone and the ozone layer shields us from harmful UV radiation. Steel is 94% iron and 6% carbon. The carbon forms complex bonds making steel so strong that you can bend an iron crowbar, but not a steel one. Steel is one of the most common construction materials, next to glass (a chemical combination of silicon), plastic (organic chemistry) and aluminum which is refined from bauxite ore using extremely high voltage--another instance of chemistry in action. ANYTHING that burns is undergoing a chemical reaction and almost always creates some form of carbon as waste.

Figure1. Chemistry in every day life

Forensic scientist… Most forensic scientists work in crime laboratories that are part of city or county legal systems where they analyze bodily fluids and tissue samples collected by crime scene investigators. In analyzing these samples, a forensic scientist identifies the presence or absence of specific chemicals within the body to help solve the criminal case. Some of the chemicals they look for include alcohol, illegal or prescription drugs, poisons, arson debris, metals, and various gases such as carbon monoxide. In order to identify these substances, a variety of chemical instruments and highly specific methodologies are used. Forensic scientists also analyze samples from criminal suspects, athletes, and potential employees. They also work on cases involving environmental contamination and animal samples for wildlife crimes. A forensic scientist usually has a bachelor’s degree that includes courses in math, chemistry, and biology

Hemoglobin Hemoglobin transports oxygen to the tissues and carbon dioxide to the lungs.

Matter is another word for all the substances that make up our world. Chemistry Chemistry is the study of the composition, structure, properties, and reactions of matter. Matter is another word for all the substances that make up our world.

Chemistry is not done only in lab… Actually, chemistry happens all around you every day and has an impact on everything you use and do. You are doing chemistry when you cook food, add bleach to your laundry, or start your car.

Antacid tablets undergo a chemical A chemical reaction has taken place when silver tarnishes or an antacid tablet fizzes when dropped into water

Chemicals A chemical is a substance that always has the same composition and properties wherever it is found. All the things you see around you are composed of one or more chemicals.

Scientific method…

Help to explain how scientists think…. Scientific method Help to explain how scientists think….

Approach … 1.Observations- look around you and ask yourself question !! 2. Hypothesis. Propose a hypothesis, which states a possible explanation of the observations. The hypothesis must be stated in such a way that it can be tested by experiments. 3. Experiments. 4. Conclusion. When the results of the experiments are analyzed, a conclusion is made as to whether the hypothesis is true or false.

Example

Scientific method cont… If we gather enough data about our subject we will be able to form a HYPOTHESIS. Hypothesis is a proposed explanation for an observation, phenomenon, or scientific problem that can be tested by further investigation! To test the hypothesis we perform EXPERIMENTS .If the experiments support the hypothesis we will perform another experiments(under various conditions) to verify our statement. After many confirmed experiments( the results are reproducible) we can CONCLUDE and state a LAW or Scientific law . A law simply says what happens but doesn't explain it (why this happens).

Scientific method cont…. Once a Law has been formulated, scientist try to develop a THEORY (unifying principle) that explains the law based on experimental methods( why nature behaved as it does ). The theory can develop by time because new facts may arise. Scientific method

Key Math Skills for Chemistry Calculating a percentage To determine a percentage, divide the parts the total (whole) and multiply by 100%. For example, if there are 8 chemistry books on a shelf that has a total of 32 books, what is the percentage of chemistry books?

Solving equations In chemistry, we use equations that express the relationship between certain variables. Let’s look at how we would solve for x in the following equation: 2x + 8 = 14 2x =14-8 2x =6 x = 6/2 = 3

Esample

Interpreting a graph A graph represents the relationship between two variables. These quantities are plotted along two perpendicular axes, which are the x axis (horizontal) and y axis (vertical) From the graph, we see that the volume of the gas increases as the temperature of the gas increases. This is called a direct relationship.

Example

Writing numbers in Scientific notation

Some facts.....

Summary of the chapter