Chemistry Study Guide (Chapters 1-6) PDF

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Important notes for chapters 1-6 for CHEM1025. These notes I made myself and are very well organized to help you pass this course. My professor was Dr. Melko and these notes come directly from his powerpoints. Send me a message if you have any questions!...

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Chemistry Study Guide Chapter 1 

The scientific method- a systematic investigation of nature that requires an explanation for the results of an experiment.

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Hypothesis- the initial tentative proposal of a scientific principle.

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Natural Law- measurable relationship

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Types of Chemistry Organic- substances with carbon Inorganic-substances without carbon Biochemistry- substances derived from plants and animals Green Chemistry- chemical processes that reduce waste and hazardous substances. Chapter 2  The Metric System Exa E 18

Deci d -1

femto -15

Peta P 15

Centi c -2

atto -18

Tera T 12

milli m -3

Giga G 9

micro -6

Mega M 6

nano -9

Kilo k 3

pico -12

 Always know 1km=1000m “unit equation”  Practice: Mass in grams of 325 mg pill? Use KHD…dcm

 Metric-English Conversions: always assume 3 sigfigs. ROUND  Compound Units 105km/hr. in m/s? -Convert km to m -Convert hr. to s 105 km

1000m

1 hr.

1 km

I hr. 3600 s

=29.2m/s  Percentages %= one quantity 100% Total sample Example: Sterling silver contains silver and copper. If SS chain contains 18.5 g of silver and 1.5 g of copper. What is the mass percent of silver in the chain? % silver= Mass of silver Mass of silver + mass of copper  Volume L*W*T= volume ^3 (all measurements must be in the same unit)  Density= Mass Volume -Usually in g/mL, or g/cm^3 Floats: object has low density than liquid Sinks: object has higher density than liquid Example: A car battering has 1275 mL OF BATTERY ACID. If the density of battery acid is 1.84 g/mL, how many grams of acid are there?

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1275 * 1.84g/ ml =2350 g  Temperature The measure of average kinetic energy of individuals particles in motion. Celsius, Fahrenheit, Kelvin. Water freezes @ 35 F, 0 C, 273 K Water boils @ 212 F, 100 C, 373 K C to K: c+273 K to C: K-273  Heat The measure of total energy, expressed in Joules (J) or calories (c) “Both beakers have the same temperature but not same amount of heat. Specific Heat: the amount of heat required to raise the temperature of I gram or a substance to 1 degrees Celsius Chapter 3 Liquids and Solids: cannot be compressed (fixed volume) Gases: can be compressed (variable volume) Solid to Gas: Sublimation Gas to Solid: Deposition Gas to Liquid: Condensing Liquid to Gas: Vaporizing Matters Classifications: 1. Mixture: composed of more than one substance, can be separated  Homogenous: salt water, air, alloys (18K gold, brass, bronze), gold foil, sterling silver, vodka  Heterogenous: sand, water, cookies, mud, fruit salad 2. A Pure Substance: composed of one substance, can’t be separated  Elements: oxygen, carbon, etc., helium

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 Compounds: water at room temperature, carbon dioxide Types of Metals: Metals  Solid at RT (except Hg, it’s a liquid)  High Melting Points and densities  Good heat conductors  Malleable (sheet shape)  Ductile (fine wire shape) Non-Metals  solid or gas at RT (except Br: liquid)  low melting points and densities  poor conductors  not malleable or ductile  Crushed into powder Semi-metals  Like silicon (brittle, poor conductor) Physical Properties

Pure Substance without changing substance composition Color and Density Mass and Melting Pt

Chemical Properties

Describes how a substance changes during reactions with other subs. Flammability Reactivity with acid

Physical Change: doesn’t alter chemical composition, only changes shape or state. Chemical Change: alters chemical composition, like gas released, light or heat released, permanent color change. Law of Conservation of Mass

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- The mass of a substance before and after a chemical change is always equal. Chapter 4 Rutherford Model An atom has central nucleus  Neg. charged e- are around a positive nucleus  Nucleus must consist of neutral particles in addition to protons. Electron 1/1836 mass Neutron and Proton 1 Atomic Notation o Atomic Number- number of PROTONS

MN: 12

o Mass Number- PROTONS+NEUTRONS

C

HOW TO FIND ELECTRONS Mass #---atomic number

AN: 6

12--6=6 electrons Isotopes Means the element has a different number of neutrons, but same number of protons. Simple Average: same # of diff. object Weighted Average: diff. objects in diff. amts “Avg. Atomic Mass” 

Gallium has two isotopes: - 69 Ga, with a mass of 68.926amu and 60.11% abundance – 71 Ga, with a mass of 70.925 amu and 39.89% abundance

- The average atomic mass of gallium is: (68.926 amu) (0.6011) + (70.925 amu) (0.3989) = 69.72 amu Bohr Model  Explains the emission spectrum Sublevels  S P D F (1s,2s,2p,3s,3p,4s,3d,4p,5s,4d)

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S- 2 electrons (1 orbital) p- 6 electrons (3 orbitals) d- 10 electrons (5 orbitals) f- 14 electrons (7 orbitals) number of electrons 2p^2 Energy level

energy sublevel

Electron Configuration Bromine has 35 electrons 1s,2s,2p,3s,3p,4s,3d,4p^(5). Chapter 5 Periodic Law- properties of elements recur in a repeating pattern when arranged by increasing atomic number.

Rows- periods or series (7) Columns- groups or families (18) Hydrogen  Loses one electron when reacts to other elements  Similar to a non-metal Columns Order (left to right)     

AKALI AKALINE TRANSITION HALOGENS NOBLE GASES

Atomic Radii  The size of an atom (decrease when you go higher and more to the right) since fewer energy levels. Abbreviated Electron Configuration If Bromine has 35 electrons

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1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p5 It’s AEC, should be 35-noble gas above (Ar) (35-18=17) 2

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5 = 17 electrons

[Ar] 4s 3d 4p

Dot Formulas should always be written in AEC, but not noble gas inside. Ionization Energy the amount of energy needed to remove an electron from an atom. The closer an electron is to the nucleus; the more energy is needed to remove that electron. INCREASING TOP, INCREASING LEFT TO RIGHT. Ionic Charge o Metals lose valence electrons and nonmetals tend to gain valence electrons, in an effort to achieve a noble gas configuration.

o Group 1 metals form 1+ ions, Group 16 elements form -2 ions.

Ion Electron Configurations The electron configuration for a positive ion is similar to the corresponding neutral, but we remove one electron for each positive charge. + Na → Na

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2

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6 1 2 2 6 1s 2s 2p 3s → 1s 2s 2p The electron configuration for a negative ion is similar to the corresponding neutral, but we add one electron for each negative charge. 2O →O 2

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4 2 2 6 1s 2s 2p → 1s 2s 2p Chapter 6 o Binary Ionic: one metal, one nm o Ternary ionic: one metal, one nm o Binary Molecular: two non-metals o Binary acid: hydrogen and one nonmetal o Ternary oxyacid’s: hydrogen, oxygen, one nonmetal Classifying Ions o Positive: Cation (left side of PT) o Negative: Anion (right side of PT) o Polyatomic ions are formed when molecules (groups of atoms) gain or lose electrons.

Examples: SO

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2+ NH 4 , 4...