Measurements and Calculations Chapter 2 Measurements and Calculations

II. Matter and Its Properties -Matter: has mass & occ space 1. Occupy space 2. Experience inertia *Inertia: resist change

*weight: (mass)(gravity) *mass: amount of matter *Law of Conservation of Mass

-NRG *ability to do work *ability to create a force over a distance some time in the future ~Chem deals mostly with 1. Thermal 2. Radiant 3. Electric

*kinetic nrg= (.5)(m)(v)2 nrg of motion *potential nrg= (m)(g)(h) nrg do to position

-Law of Conservation of NRG (1st) -States of Matter 1. Solid 2. Liquid 3. Gas 4. Plasma **See Website Ex’s** http://www.chem.purdue.edu/gchelp/liquids/character.html

-Properties & Changes *can be used to classify subst 1. Physical: observ or measure without alter ident of the material. ex: color 2. Chemical: change that alters ident ex: burn wood, rust iron

*Chem Rxn: pg13 *Reactans yields Products A + B ----> AB *Exother: acid + HOH -->heat + ??? *Endother: ice + heat ---> HOH

Indicators of Chem Rxn’s 1. Produce heat & light 2. Produce gas 3. Produce precipitate **K Demo** *precip.: solid formed from a solution

III. Classification of Matter -Mixture *Heterogeneous: pg 16 ex: veg. soup, clay + water *Homogeneous / Solutions: pg16 ex: air, salt HOH

*Homogeneous / Solutions: pg16 ex: air, salt HOH ~components of any mixture can be separated from each other by physical methods

-Pure Substances 1. Same property 2. Same composition 3. Can not be separated without changing the ident ex: electrolysis

*element: ex: K, Pb *chem. Cmpnd:ex: HOH, sugar *Law of Definite Composition: ex: CH4 C=75% H=25%

IV. Chemical Elements *Groups: vert *Periods: horz -Symbols:

-Types of Elements (pg21) 1. Metals: 2. Nonmetals: 3. Metalloids: 4. Noble Gas:

II. Units of Measurements Factor/Label: ex’s Derived Units Table 2-3 pp 36

Density: = (m) / (v) units?? g/ml ***table 2-4 pp 38** Volume: = (l) (w) (h) units?? cm3

A. Heat and Temp *Temp: *Heat: ex’s: pp 511-512

-Kelvin: Freeze: 273.15 Boil: 373.15 K = (C) + 273 0 K is absolute 0

Celsius Freeze = 0 °C Boil = 100 °C ° C = (5/9) (F - 32)

Fahrenheit: Freeze = 32 °F Boil = 212 °F °F = (9/5) (°C) + 32

-Units of Heat *Joule (J) *Calorie (c): c = 4.184

Paper Cup Demo http://www.youtube.com/watch?v=gQpUQu9bkAc&feature=related #2 (boiling water in a paper cup)

Heat Cap. and Spec. Heat *HC: pp 513 Fig. 17-1

= heat lost or gained (J or Cal) mass(g) X ∆ in Temp (°C) Spec. Heat = heat lost or gained (J or Cal) mass(g) X ∆ in Temp (°C) Cp = ______q______ (m) (∆ T)

Examples Determine the specific heat of a material if a 35g sample absorbed 48 J as it was heated from 293 K to 313 K. A: .069 J/(g*K)

Examples 2. How much heat is needed to raise the temperature of 5 g of gold by 25 C? A: 16 J

Examples 3. If 980 kJ of energy are added to 6.2 L of water at 291 K, what will the final temperature of the water be? A: 329 K

III. Scientific Measurements *Accuracy: *Precision: ex’s: pp 44 *Percent Error = Valueacc - Valueexp Valueacc

-Proportional Relationships Directly: y/x = k or y = kx Inversely: xy = k or y = k/x **ex’s and graphs http://mathcentral.uregina.ca/QQ/database/QQ.09.00/ellis1.html