Introduction to IB Chemistry & Section 1.1. Ms. Kiely Coral Gables Senior High IB Chemistry SL

Transcription

1 Introduction to IB Chemistry & Section 1.1 Ms. Kiely Coral Gables Senior High IB Chemistry SL

2 Welcome to IB Chemistry SL SYLLABUS

3 Welcome to IB Chemistry SL Today you are receiving the IB Data Booklet. Bring this to class every day! Some general rules and expectations: -Bell-Ringer: commonly a test question -Bathroom Pass: 1 pass only, must be returned to me -Phones and other electronic devices: not allowed -Hall Passes: no one goes anywhere the first 15 minutes of class -Water: Yes Food: No -Websites: CGHS website & Managebacc SIGN IN TO THE CLASS ON THE CGHS WEBSITE by clicking Add to my Class List

4 After School For IB students only: -After each test or every couple of tests, you ll be required to complete test rebuilds as classwork or homework. However, students who earn a C or lower on a test are recommended to complete their rebuilds after school with me on Tuesdays (sometimes Mondays in the case of a Faculty Meeting). Parents/guardians may be contacted in order to insist on this opportunity. -THIS IS NOT A TUTORING -This IS the time to make-up a lab

5 IB Chemistry Score Breakdown Percent Breakdown What is this!? Internal Assessment (IA) 20% of final IB score Individual experiment with written report Paper 1 20% of final IB score 30 multiple-choice questions on core topics (Topics 1-11) Paper 2 40% of final IB score Short-Answer and Extended-Response Questions/Prompts on core topics (1-11) Paper 3 20% of final IB score Section A: data-based questions Section B: short-answer and extended-response questions from one option (option A, B, C, or D)

6 Class Exams Exams in this class will mimic the IB exam. You will have to answer Paper 1 style questions and Paper 2 style questions for the topic at hand. In some instances, you will also be timed. During Paper 1, you are not allowed a calculator. We will prepare for this during class.

7 Group 4 Project The group 4 project is a student generated, student planned, and student produced interdisciplinary research project uniting the three IB sciences offered at CGHS: Biology, Chemistry, and Physics. You will be randomly grouped with other students from each discipline. Group 4 is graded by the teacher and is part of the class grade. It is also included in your final IB score. More details on Group 4 to be announced at a future date with the other IB science teachers.

8 This is the book that will be used for the entirety of this course. PDF versions of each chapter are available for you on the CGHS website. Older version of the book are quite useful and will generally not hinder your understanding of the material. Pearson Baccalaureate Standard Level Chemistry 2nd Edition Catrin Brown, Mike Ford

9 Chemistry is the study of matter, so... what is matter? Matter is anything that takes up space by having mass. So, what is mass? Mass is the result of being made up of atoms, or any of the subatomic particles: protons, neutrons, electrons. How many types of atoms are there? According to the IUPAC, (International Union of Pure and Applied Chemistry), there are 118 elements currently known to us in our universe. Therefore there are 118 distinct types of atoms that can be found in our universe or synthesized. Section 1.1 Why do a block of gold and a piece of carbon that are the same size and dimensions weigh differently?

10 Elements are substances that cannot be broken down into a simpler component. If the atom of a particular element is broken down, then that particular element will no longer be represented. The atom is the smallest unit that still represents an element. Is the atom the smallest unit that represents matter? Is it a fundamental particle? Video:

11 Structure of the Atom Protons and neutrons are located in the nucleus, or center, of the atom. Protons and neutrons are roughly the same size in mass. Together, protons and neutrons are referred to as nucleons. Electrons are much smaller than protons and neutrons, and are located a very far distance from the nucleus in an area referred to as the electron cloud which surrounds the nucleus. Protons, neutrons, and electrons are all referred to as subatomic particles.

12 The discovery of subatomic particles, the particles that make up the atom, proved that the atom is not a fundamental particle. In fact, protons and neutrons are not fundamental either; they are made up of smaller particles called quarks. (In IB, we won t be too concerned with quarks.) The electron is considered to be a fundamental particle since we have yet to prove that the electron is made up of smaller particles.

13 Periodic Table Atomic number: based on the number of protons found in the nucleus. The atomic number helps identify which element an atom belongs to. Chemical symbol: each element is denoted by either one upper-case letter, or one upper-case letter followed by a lower-case letter. Relative Atomic Mass (RAM): the average mass of an atom of that particular element.

14 States of Matter Matter exists in different forms depending mainly on two factors: Temperature Pressure States of matter are characterized by the different energies of the particles. This is known as kinetic energy theory of matter.

15 Element: an element is anything that consists of one type of atom. *Molecule: the term molecule is often misused. The term molecule is also used to describe atoms that are bonded together; however, it is only used when the bonded atoms are nonmetal atoms! Also, the nonmetal atoms that are bonded together can be of the same element or be of different elements. Compound: a substance made by chemically combining two or more elements. It has different properties from its constituent elements. Matter is either pure or mixed. Pure matter is anything that is made up of only one type of atom (an element), or one type of compound. Mixed matter is anything that is made up of different elements and compounds that are not chemically bonded together.

16 Matter can further be categorized as a substance or a mixture. Substances Mixtures These are both umbrella terms for types of matter in our world. A substance is anything with a uniform chemical composition, meaning it is made up of one type of atom (an element) or one type of compound ONLY (a compound). A mixture is anything with a mixed, non-uniform chemical composition; mixtures contain more than one type of element and/or compound that are NOT chemically bonded to each other, and so retain their individual properties.

17 Element, Compound, or Mixture?

18 As was mentioned on the last slides, the chemical composition of a mixture is NOT uniform. Mixtures are made up of many substances (elements, & compounds) in which no chemical combination has occurred- simply a physical combination has occurred. However, in order to determine whether a mixture is homogeneous or heterogeneous, you must look at its PHYSICAL appearance. If it physically looks uniform throughout, then it is homogeneous. Homogeneous mixtures are also called solutions. If it physically looks variable throughout (i.e. if it has visible layers in it, visible particles in it, etc), then it is heterogeneous.

19

20 Classify each of the pictures by stating the correct label for the blanks below each image: Element Compound Mixture of different compounds MIxture of elements Mixture of elements and compounds Each circle represents an atom and each different color represents a different kind of atom. If two atoms are touching, then they are bonded together (compound).

21 ANSWERS: 1. Compound 2. Mixture of different elements 3. Mixture of elements and compounds 4. Mixture of different compounds 5. Element 6. Compound 7. Element 8. Mixture of elements and compounds 9. Mixture of elements 10. Mixture of elements and compounds 11. Compound 12. Mixture of different compounds 13. Mixture of different compounds 14. Mixture of different compounds 15. Mixture of different compounds

22 Chemical Formula The chemical formula of a compound or molecule contain the chemical symbol(s) of the element(s) that are part of it, and also use subscripts to show the number of atoms of each type of element in the compound or molecule.

23 Chemical Equations The formation of a compound is an example of a chemical change. For example, in the synthesis of water, hydrogen atoms and oxygen atoms chemically separate from themselves and rearrange themselves to produce a new substance, water. A chemical change occurs whenever the chemical composition of something is changed by means of an energy change. Remember that based on the Law of Conservation of Mass, matter can neither be created or destroyed, only rearranged! Chemical reactions can be represented by chemical equations. A chemical equation displays how atoms are arranged prior to a chemical change, and how they are arranged after a chemical change.

24 Coefficient Since atoms are neither created nor destroyed, only rearranged, during a chemical reaction, the total number of atoms of each element must be the same on both sides of a chemical equation. Only when the number of atoms of each element is equal on both sides of an equation is the equation correct: this means it is balanced. We use coefficients to help us balance equations. Coefficients are the numbers in front of each reactant and product. If there is no coefficient written, then the coefficient for that substance is 1. You do not need to write the number 1 in this case. Coefficients give information on the molar ratio between all the substances in an equation, meaning they express moles. In the example above, two moles of hydrogen gas react with one mole of oxygen gas to produce two moles of water.

25 Balancing Chemical Equations Example (from pg. 7) Write an equation for the reaction of thermal decomposition of sodium hydrogencarbonate (NaHCO3), into sodium carbonate (Na2CO3), water (H2O), and carbon dioxide (CO2). REMEMBER -when you are balancing an equation, you may alter the coefficient BUT NEVER THE SUBSCRIPT of a chemical formula. -a correctly balanced equation has all coefficients in SIMPLEST FORM. -a substance with a blank coefficient has a coefficient of 1.

26 Balancing Chemical Equations Example What is the coefficient for O2(g) when the equation below is balanced? A. 2 B. 3 C. 5 D. 7 C3H8(g) + O2(g) CO2(g) + H2O(g)

27 Common Formulas A reminder of some of the formulas of common substances that you will be expected to know. -The diatomic elements: Iodine (I₂), Hydrogen (H₂), Nitrogen (N₂), Bromine(Br₂), Oxygen(O₂), Chlorine (Cl₂), Fluorine (F₂) I Have No Bright Or Clever Friends -Water: H₂O -Carbon dioxide: CO₂ -Methane: CH₄ -Sulfuric acid: H₂SO₄ -Calcium Carbonate: CaCO₃ -Sodium chloride: NaCl -Hydrochloric Acid: HCl

28 Homework: 1. Read the remaining slides from this slideshow (available on CGHS website) on scientific notation and significant figures, and complete the Significant Figures Worksheet (you may print and write on this sheet or just answer on a separate sheet of paper). 2. Bring a calculator next class. A 4-function calculator is fine for now.

29 Quantitative Chemistry Calculation and quantitative material lends to a large portion of what will be covered in IB Chemistry. It is essential in almost every topic of this curriculum for you to have a basic knowledge of algebra, and confidence in applying that knowledge. In fact, of all the topics, topic 1 will take the most time to cover. Today we will refresh on: -Scientific Notation -Significant Figures

30 Scientific Notation Six hundred two sextillion atoms are in a single gram of hydrogen! This is the written number: 602,000,000,000,000,000,000,000 This is a very large number to work with. We can write this number and work with this number more simply in scientific notation: 6.02 x 10²³

31 Scientific Notation The coefficient must be greater than or equal to 1 and less than 10, and must contain all the significant digits in the number x 10^4 is not in correct scientific notation, since the coefficient is greater than x 10^4 is also not in correct scientific notation, since the coefficient is less than 1. The base is always 10. The exponent is the number of places the decimal was moved to obtain the coefficient. A positive exponent expresses places to the right of the decimal. A negative exponent expresses places to the left of the decimal.

32 Scientific Notation Coefficient 6.02 x 10²³ Exponent A positive exponent indicates a number greater than 10, and also indicates how many times the coefficient must be multiplied by 10. The positive exponent lets how know how many times the decimal point should move to the right in order to write the number in standard notation. Coefficient 8 x 10^-6 Exponent A negative exponent indicates a number that is less than 1, and also indicates how many times the coefficient must be divided by 10. The negative exponent lets how know how many times the decimal point should move to the left in order to write the number in standard notation.

33 Scientific Notation Examples: 1) Express 503,000,000 in scientific notation. 2) Express 9.42 x 10^-7 in standard notation. 3) Express x 10^5 in standard notation.

34 Significant Figures Significant figures are important when gathering, working with, and reporting measurements. Measured numbers can be pretty unhelpful if you are not sure how precise they are- significant figures help us keep our measurements as precise as possible! Helpful Khan Academy Video: g-figs-pre-alg/v/significant-figures

35 1. All non-zero digits are significant. For example: 123. (3 sig figs) 2. Zeros between non-zero digits are significant. For example: (5 sig figs) 3. Zeros to the left of the first non-zero digit are not significant. For example: 1.02 (3 sig figs) 0.12 (2 sig figs) (2 sig figs) 4. If a number ends in zeros to the right of the decimal point, those zeroes are significant. For example: 2.0 (2 sig figs) 2.00 (3 sig figs) {This signifies greater accuracy.} These rules apply to measured quantities which are non-exact. If you are told that a number is exact then there is no uncertainty; i.e., the number is good to an infinite number of sig figs. Exact integers fall in this category.