Unit 1 Study Guide

1.1 The History of Chemistry Branches of Chemistry Organic chemistry- study of living things (carbon-containing compounds) Inorganic chemistry- study of non-organic substances (non-living), many bonded to metals Physical chemistry- study of properties and changes of matter and their energy Analytical chemistry- identification of components and compounds of materials Biochemistry- study of substances and processes in living things Theoretical chemistry- use of mathematics to understand chemical behavior and predict properties of new compounds Basic Research- done to increase knowledge, ex: how and why reaction occurs and what properties of a substance are. Can be found by accident, ex: Teflon, Positron Applied Research- carried out to solve a problem, ex: refrigerants that don’t pollute ozone Technological Development- improve quality of life, ex: computers, biodegradable materials 1.2 Laboratory Safety Classes of Fires Class A fire- trash, wood, paper Class B fire- liquids Class C fire- electric 1.3 The Methodology of Science Scientific method- logical approach to solving problems by: Observing and collecting data Formulating hypotheses Testing hypotheses Formulating theories supported by data Requirements for formulating valid hypothesis: use background information obtained by research FiLCHERS Falsifiability- must be possible to prove a thing false before accepted as true Logic- naturally follow from others of same type Comprehensiveness- all evidence must be evaluated, not just evidence that matches Honesty- all evidence must be shown at risk of failing experiment Replicability- any experiment can be replicated with same results Sufficiency- evidence needs to be sufficient enough to prove theory

Limitations of science opinion, morality, supernatural, religion

Science- study of something that exists Pseudoscience- myths or beliefs that could be scientific but are false or do not have enough evidence to be true 1.4 Units Seven SI Units Length- l- meter- m Mass- m- kilogram- kg Time- t- second- s Temperature- T- Kelvin- K Amount of substance- n- mole- mol Electric Current- I- ampere- A Luminous intensity- Iv – candela- cd Three Common Conversion Factors 2.54 cm/1 in 2.2 lbs/1 kg 1.06 qt/1 L Metric system is better because it increases by 10s Prefixes giga- G- 109 – 1 000 000 000 mega- M- 106 – 1 000 000 kilo- k- 103 – 1 000- Kabir hecto- h- 102 – 100- hates deka- da- 101 – 10- dark basic- 100 – 1- bitches deci- d- 10-1 – 1/10- drinking centi- c- 10-2 – 1/100- cum milli- m- 10-3 – 1/1000- molecules micro- u- 10-6 – 1/1 000 000 nano- n- 10-9 – 1/1 000 000 000 Mass- measure of quantity of matter, does not depend on gravity, stays the same everywhere Weight- measure of gravitational pull on matter

1.5 Uncertainty and Significant Figures Use measuring devices to the finest calibration mark plus an estimated digit Accuracy- closeness of measurement to correct or accepted value

Precision- closeness of a set of measurements of same quantity measured in same way Significance of Zeros Zeros between nonzero digits significant, ex: 87 009 km five significant figures Zeros in front of all nonzero digits NOT significant, ex: 0.0009 one significant figure Zeros at end of number and to right of decimal point significant, ex: 85.00 four sigfigs Zeros at end of number to left of decimal significant if measured, ex: 2000. four sigfigs Scientific notation 856.79 = 8.5679*102 Always write based on smallest number of significant figures in equation 1.6 Dimensional Analysis Multiply by the conversion factor, ex: 8.00 cm*1 in/2.54 cm=3.15 in Write so unit of previous numerator is following denominator, allows you to cancel out units 1.7 Density Density=mass/volume, characteristic physical property, as mass increases so does volume so any amount of a substance always has same density 1.8 States of Matter Solid- fixed volume and shape, molecules in rigid structure Liquid- fixed volume but not shape, molecules are able to slide past one another Gas- no fixed volume or shape, fills up the container Exothermic reaction- plasma to gas, gas to liquid, liquid to solid, releases heat Endothermic reaction- solid to liquid, liquid to gas, gas to plasma, absorbs heat 1.9 Classification of Matter Element- pure substance, cannot be broken down into simpler parts, made of one type of atom Compound- made of 2 or more elements, can be broken down into simple substances Substance- every sample of same substance has same properties, some composition, cannot be separated physically Mixture- different substances combined, can be separated by physical means Homogeneous mixture- same proportion of components throughout Heterogeneous mixture- not uniform throughout Physical property- something that describes a substance, ex: boiling point, density, malleability Physical characteristic- what a substance looks like, ex: color, shape, size

Physical properties- characteristic that can be observed or measured without changing identity Chemical property- ability of substance to undergo changes that transform into new substance, ex: burning, rusting Physical changes- change that does not involve identity change, ex: cutting, melting, boiling Chemical changes- change where one or more substances are converted into another, reactants and products It is a chemical reaction if a chemical change occurs, ex: evolution of heat, emission of light, color change, rusting, rotting, significant physical change, formation of gas or precipitate 1.10Forms of Energy Energy- capacity to do work or supply heat, expressed in joules (kg*m2/s2) Kinetic energy- energy of motion, ex: waves, electrons, atoms Potential energy- stored energy of composition or position, ex: hold a rock up Potential energy turns into kinetic energy once released by another force An object accelerating faster gives it more kinetic energy More kinetic energy means molecules are moving faster, creating heat Forms of Energy Mechanical, M Radiant, r. Chemical, C Heat, h Electrical, e Nuclear, n Law of conservation of energy- energy is created or destroyed, ex: in gay sex even though the guys are sweating profusely, the energy is just transferred from cock to anus 1.11Temperature Common temperature scales- Celsius, Fahrenheit, Kelvin Absolute zero is -273.15 degrees Celsius Fahrenheit= 9/5C+32 Heat is measured by energy which measures how fast molecules are moving Temperature measures the degrees or the average kinetic energy