Chemistry Study guide Please add content to it, and feel free to share it w/ who ever Chapter II Chemistry is the Study of matter ● Matter has the properties of Volume and Mass ● Mass is volume ● Volume Takes up space Ways to Classify Matter Solids ● Molecules are compact, little vibrations, very organized and have a set volume Liquids ● Takes the shape of the container which means there is no set shape. Molecules are just as compact as solid molecules and in some cases, even more compact (h20). ● not organized, and a lot of vibrations Gases ● No set shape and volume of a gas CAN change Mixtures ● A combination of two or more pure substances ● are not chemically bonded ● Retains their original properties ● Can be combined in any ratio Ways to Separate Mixtures ● ● ● ● ● Filtration (uses particle size) Distillation (uses boiling points) Chromatography (based on difference in polarities) Centrifuging (using difference in density) Magnetism (using magnetism to separate)(only Cobalt, iron, and manganese are magnetic) Pure Substances: ● Are elements and compounds with their own unique Physical and Chemical properties Physical: ● Soluble ● Boiling point ● color ● freezing point ● density ● magnetism ● PH ● malleable Chemical ● Flammability ● Smell ● Does it react w/ acid? w/ water? Chapter III ● Back in the Day, they called chemist alchemist Elements ● Each element of the same type has the same number of protons. the atomic number is the number of protons Metals ● They conduct electricity ● They are malleable (able to be bent into any state) ● They conduct heat ● They are ductile (able to be bent into wires) ● Most of them are lustrous (shiny) Non-Metals ● Cannot conduct electricity ● they’re are not ductile ● Not malleable ● Doesn’t conduct heat Metalloid ● Semiconductor (used in computers) ● Si - Silicon Chemical symbols for major elements H=hydrogen Ar=Argon Li=lithium Kr=Krypton Na=sodium Xe=Xenon K=potassium Al=Aluminum Be=Beryllium Pb=Lead Mg=Magnesium Si=Silicon Ca=Calcium P=Phosphorus Sr=Strontium S=Sulfur Ba=Barium Cl=Chlorine Mn=Manganese Br=Bromine Fe=Iron Se=Selenium Ni=Nickel Rb=Rubidium Cu=Copper I=Iodine Zn=Zinc Ag=silver Au=gold Hg=Mercury B=boron C=carbon N=nitrogen O=oxygen F=Fluorine Ne=Neon He=Helium History Democritus (400 B.C. -300 B.C.) ● First to theorize that all matter compose of atoms ● Atoms come means indivisible ● Not based on scientific evidence John Dalton (1803) ● English school teacher first to prove existence of atoms ● Theorized that atoms are (*= true) ○ Tiny* ○ Indivisible ○ unchanged in chemical reaction ○ no subatomic particles ○ uniformly dense JJ Thomson (1890) ● Determined that atoms are composed of + and - stuff ● Created the plum pudding model ● Proved his theory based on cathode ray experiment Ernst Rutherford ● Created the gold foil experiment ● Polonium gives off a charged particle called an Alpha particle ● In the experiment, he show alpha particles at gold foil ○ 99.9% made it through ○ 0.09% deflected to the side ○ 0.01% bounced back ● His experiment that in the center of every atom was a small, dense, positively charged object ● Here is a video which describes the experiment: http://www.youtube.com/watch?v=5pZj0u_XMbc Law of Constant Composition ● “The same compound is always composed of the same elements in the same ratio” Subatomic particles Charge Relative charge mass Relative mass location Electrons -1.6x10-19 -1 9.11x10-31 0 amu surrounds the coulombs atom Protons 1.6x10-19 coulombs +1 1.67x10-27 1 amu nucleus Neutrons 0 0 1.67x10-27 1 amu nucleus Nuclear Symbol Notation 12 6 C ● The number on the top is the Mass number, and the number on the bottom is the Atomic number Example 1: 12 C= 6 protons, 6 neutrons 13 C=6 protons, 7 neutrons 14 C= 6 protons, 8 neutrons Hyphen notation Carbon-12 ● 12 is the mass number ● that means it has a mass number of 12, which means it has 6 protons and 6 neutrons Uranium ● 99% of uranium is uranium 238 ● The rare form (the form used in bombs) is uranium 235. AKA enriched uranium Compounds Compound: ● A combinations of two or more elements which are 1. Chemically bonded 2. have unique physical and chemical properties, different from their elements 3. Can only be combined in a whole number ratio Types of Compounds ● Covalent ○ Consist of two non metals ● Ionics ○ Consist of one metal and a nonmetal Chapter IV: Nomenclature Rules of Covalent nomenclatures 1. Always put the more metallic element first 2. Use greek prefixes to indicate ratio of atom a. 1: Mono 6: Hexa b. 2: Di 7: Hepta c. 3: Tri 8: Octa d. 4: Tetra 9: nona e. 5: Penta 10: Deca 3. Drop last syllable for the second element. add “ide” 4. Drop starting mono on second element 5. Don’t reduce subscript Ionic Compounds Ions ● Ions with a positive or negative charge ○ Gains or loses an electron Cations ● Atoms with a positive charge, formed from losing and electron Anions ● atoms with a negative charge, formed from gaining and electron Ionic nomenclature 1. Write the metal first 2. use charges to determine the ratio of cations to anions a. NO greek prefixes 3. add “ide” to the last element 4. Reduce subscript (only IONIC) 5. Ionic compounds must have a neutral charge Metals with more than 1 charge ● Metals always have a positive charge ○ use roman numerals to indicate charge ● Ionic compounds with more than two elements are called polyatomic ions Chapter V: Measurements and Calc. 1. Scientific Notation 2. Metric unit 3. Uncertainty measurement 4. Density 6. Best fit line 7. Dimensional analysis Scientific notation ● Useful for very big or small numbers ● Based on power 10 ● Speed of Light = 3.00 x 10^8 ● Charge of an electron = -1.60 x 10^-19 ● Radius of a hydrogen atom = 5.29 x10^-11 ● Mass of the earth is 5.98x1024 Metric system ● Length (meters) ● Mass (grams) ● Temperature (celsius) ● Time (seconds) ● Brightness (lumen) ● Quantity (mol) ● Charge (coulombs) Uncertainty in Measurement ● No scientific instrument can give a perfect measurement, therefore, the last numbers recorded when collecting data are an estimate Significant Figures ● A scientific method for rounding numbers ; rules to determine if a number is “significant” ○ All non zero integers are significant ■ 234 3 sf ■ 26,754 5 sf ○ Leading zeros are never significant ■ 00254 3 sf ■ 0674.2 4 sf ○ Captive zeroes are always significant ■ 101 3 sf ■ 50202 5 sf ○ Trailing zeroes are significant if there is a decimal point anywhere in the number ■ 1.00 3 sf ■ 100 1 sf ■ 10.00 4 sf. ● A calculator cannot be better that its worst measurement ● Density = Mass/Volume ○ ex: 452.0/ 350 = 1.291428571 = [1.3 g/ml] ● A number calculated by addition or subtraction cannot have more decimal places than the measurement with the least numbers of decimal places ○ ex: 24.367g + 120.23g + 1.1112g = 145.7082g = [145.71] ○ ex: 273.15 + 25 = 298 ○ ex: 297.1 k - 273.15 = 23.95 = [24.0] Chapter VI Percentage Composition ● Percent = Part/Total x 100 Empirical vs Molecular ● H2O2 is the Molecular HO is the Empirical ● N2O4 is the molecular NO2 is the Empirical ● P3O9 is the Molecular PO3 is the Empirical ● C6H12O6 is the molecular H2O is the Empirical ● H2O is the molecular H2O is the Enpirical How to Find the Empirical Formula 1. Divide the Molar Mass of the Molecular Formula (given) = Whole Number Molar Mass of the Empirical formula(given) 2. Multiply the whole number by the subscripts Empirical Formula Problem ● A mineral is found to 50% g Sulfur and 50.0 g Oxygen. What is the empirical formula of this compound? ○ 50.0 x 1molS = 1.5576 mol S = 1 , 50.0 x 1mol O = 3.125 molO =2.006 1 32.1 gS 1.5576 mol S 1 16.0 gO 1.5576 =[SO2] Mole ● A mole is 6.02x1023 ● used to measure atoms Chapter VII Law of Conservation of Mass(Matter) ● Matter cannot be created or destroyed (except in a nuclear reaction) ● The mass of substances produced (products) by a chemical reaction is always equal to the mass of the reacting substances 4 Signs of Chemical Change ● Produce a gas ● Color change ● Formation of precipitate (solid formed from mixing solids) ● Change in energy 5 Types of Chemical Reactions ● Synthesis ○ Mg+O2 -> MgO ● Decomposition ○ CO2 -> C + O2 ● Single Displacement ○ AB+C -> AC +B ■ Only occurs if the lone element is more reactive than the bonded one. It will be shown on the activity series ● Double Displacement ○ AB+CD -> AD + CB ■ Metals always first ● Combustion reaction ○ C6H12O6+O2 -> CO2 + H2O ■ All combustions reactions have Carbon and Hydrogen in different ratios Chapter VIII Solutions A Solution is..: ● Homogenous mixture. A mixture in which the individual component cannot be distinguished Solute: ● The substance in lesser amounts in a solution Solvent: ● The substance in the greatest amount in a solution The universal solvent is water The Three types of Electrolyte solutions 1. Strong electrolytes a. Great conductor of energy i. This is because they dissociate completely in water. ii. Dissociate: break up into their ions completely b. All soluble compounds, Strong acids are STRONG electrolytes ● Strong Acids ○ Hyrdrochloric acid: HCL ○ Hydrobromic Acid: HBr ○ Hydroiodic Acid: HI ○ Nitric Acid: HNO3 ○ Sulfuric Acid: H2SO4 Practice Test Section 1: Multiple choice 1. Which one of the following option is not a way to separate mixtures A. Distillation B. Concentration C. Chromatography D. Magnetism 2. An example of a chemical property is A. Smell B. density C. Boiling point D. Soluabilituy 3. Mixtures are ____ A. Chemically bonded B. Only combined in one ratio C. Created of 3 or more pure substances D. All of the above 4. Democritus created which theory A. Matter is composed of atoms B. Atoms have positive and negative charges C. Atoms contain a nucleus D. Matter can be broken down completely 5. John Dalton correctley theorized that A. Atoms or tiny B. indivisible C. uniformly dense D. unchanged in chemical reactions E. There are no sub-atomic particles F. A and B G. C and E H. All of the above 6. The law of Constant composition proves that A. Atoms cannot be broken down B. compounds are made of the same element in the same ratio C. Elements create compounds D. Compounds cannot be decomposed 7. Who created the plum pudding model? A. J.J. Thomson B. John Dalton C. Ernest Rutherford D. Democritus 8. Which of the following is NOT matter A. Virus B. Air C. Light D. Blood 9. Which one was discovered first? A. Protons B. electrons C. Nuetrons 10. Which family is only solids A. Halogen B. transitions metals C. nitrogen family D. alkali earth metals Fill in the blank 1. Chris?