Transcript CHAPTER 1
CHAPTER 1 CE CHEMISTRY MATTER Anything that has mass and occupies space Weight Mass Measure of the quantity of matter Law of conservation of matter Measure of earth’s gravity Matter cannot be created or destroyed States of matter Solid Liquid Gas PROPERTIES OF MATTER THE PROPERTIES OF MATTER CANNOT BE BROKEN DOWN WITHOUT A CHEMICAL CHANGE PHYSICAL PROPERTIES Such properties are color, density, boiling point , melting point, and hardness PHYSICAL CHANGE- Properties never change Liquid turning into a gas CHEMICAL PROPERTIES The way a substance reacts with another substance 2Na(s) + Cl2(g) 2NaCl(s) CHEMICAL CHANGE-Properties are altered SUBSTANCES PURE SUBSTANCE - Properties the same ELEMENT - cannot be broken down by a chemical change. Silver, gold or aluminum COMPOUND - two or more elements that have been chemically bonded together. This can be broken down chemically into the elements. Sugar, baking soda, etc. MIXTURES MIXTURE - Each substance retains their properties HOMOGENEOUS - all particles are in the same phase, a uniformed mixture. Salt water or air HETEROGENEOUS - all particles are not in the same phase, not uniformly mixed. Sand or wood MIXTURES CAN BE SEPARATED BY PHYSICAL MEANS Filtration, chromatography, or distillation (depends on volatility) SOLUTIONS Solutions are usually homogenous liquids You can have solutions that are a mixture of gas and liquid. Also you can have gas solutions like air. ATOMS AND MOLECULES MOLECULES Smallest particle in a compound Diatomic molecule has two same atoms (know these), Hydrogen gas(H2), Nitrogen gas(N2), Oxygen gas(O2), Fluorine gas(F2), Chlorine gas(Cl2), Bromine liquid(Br2), Iodine solid(I2) Polyatomic molecules have more than two elements in it ATOMS Smallest particle in a element All elements are single atoms Carbon (C), Aluminum (Al), except for the diatomic molecules SI UNITS Length is measured in METERS m Mass is measured in KILOGRAMS kg Time is measured in SECONDS s Temperature is measured in KELVIN K Amount of substance is measured in MOLES mol CONVERSIONS THINGS TO REMEMBER In the metric system, the smaller prefix unit will always have a larger number than the prefix unit it is equal to. 1000 m = 1km (overhead) METER IS A SMALLER PREFIX UNIT Kelvin is absolute zero or -273.15 oC. You can not have a temperature lower than this so KELVIN CAN NEVER BE A NEGATIVE NUMBER oC + 273 = K K - 273 = oC ROUNDING NUMBERS OFF In a series of calculations carry all digits unit the final solution, THEN ROUND If a digit needs to be rounded If it is less than 5, the preceding digit remains the same If the digits are equals or is greater than 5, the preceding digit is increased by one. UNCERTAINTIES IN MULTIPLICATION, DIVISION, ADDITION, AND SUBTRACTION Multiplication and division Significant figures are the same as the least precise (number with the smallest number of significant figures) measurements Addition and subtraction The answer will have the same number of digits beyond the decimal point as the integer (that was added or subtracted) with the least accurate number (last significant number is in the highest place holder) SCIENTIFIC NOTATION All chemistry uses scientific notation Uses the base 10 1000 = 10 x 10x 10 =103 0.001=1/1000=1/10 x 1/10 x 1/10=10-3 PERCENTAGES Calculating percentages Percent =number of specific items x 100 Total items in the group DENSITY Density Measure of the mass of a substance that occupies one unit of volume Density = mass = gram = g Volume Centimeters cubed cm3