Reveiw Exam 2 PDF

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Review Exam 2 Chapter Six Section 1 -

Noble gases are not found in nature they are combined with other elements. Compounds form when electrons are transferred (ionic) or shared (covalent) to complete the octet rule. Ionic Bonds: are formed when the valence electrons of a metal are transferred to atoms of nonmetals. Covalent Bonds: are formed when atoms of nonmetals  share their valence electrons. Ionic Bonds are the strongest type of bonding. Hydrogen acts like it needs only one more electron. Ions: form when atoms lose or gain electrons to form a stable electron configuration. (have an electrical charge, +, -) Groups 1A, 2A,3A lose their electrons because their ionization energies are low. Forming atoms with a positive charge. Groups 5A, 6A, 7A gain electrons because their ionization energies are high. Forming atoms with a negative charge.

Section 2 -

Ionic Compounds consist of positive and negative ions. Ions are held together by the strong electrical attractions between opposite charges, called an ionic bond. Noble gases have a stable electron configuration and do not form ionic compounds. The physical and chemical properties change when an element forms an ionic compound. Chemical Formula: represents the symbols and numbers of atoms or ions in the lowest whole-number ratio. The sum of the ionic charges is always zero. Metal ions are written first, followed by an ion from a nonmetal Formula Unit: the group of ions that contains the lowest ratio of ions in an ionic compound

Section 3 -

Naming Ionic Compounds: - Identify the Cation and Anion - Name the cation by its element - Name the anion by using the first syllable of its element name followed by ide. - Write the name for the cation first and the name for the anion second. Ie. Magnesium nitride.

Review Exam 2 -

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Transition Elements and Representative Metals of Groups 4A and 5A - Can lose s electrons from its highest energy level as well as d electrons - Can form two or more positively charged ions - Are described as having a variable charge - Exceptions are Zinc, silver and cadmium (which only have one ion) For metals that form more than one ion roman numerals equal to the ionic charge are written in parentheses after the metal name. Ionic Compound Formulas - The first part of the name that describes the metal ion, including its charges - The second part of the name that specifies the nonmetal - Ex. chromium(III) bromide CrBr3

Section 4 Polyatomic Ions: - NH4 +(ammonium) - NO3 - (nitrate) - CO3 (2-) (carbonate) - HCO3 - (hydrogen carbonate or bicarbonate) - OH - (hydroxide) - NO2 - (nitrite) - PO4 (3-) (phosphate) -

The names of the common polyatomic anions - End in ate (nitrate) - With one oxygen less end in ite (nitrite) - With hydrogen use prefix hydrogen (bi) (hydrogen carbonate or bicarbonate) Hydrogen

OH (-)

Hydroxide

Nitrogen

NH4 (+)

Amnomium

NO3 (-)

Nitrate

NO2 (-)

Nitrite

ClO4 (-)

Perchlorate

ClO3 (-)

Chlorate

ClO2 (-)

Chlorite

Chlorine

Review Exam 2 Carbon

Sulfur

Phosphorus

Chromium

Manganese

ClO (-)

Hypochlorite

CO3 (2-)

Carbonate

HCO3 (-)

Hydrogen Carbonate

CN (-)

Cyanide

C2H3O2 (-)

Acetate

SCN (-)

Thiocyanate

SO4 (3-)

Sulfate

HSO4 (-)

Hydrogen Sulfate

SO3 (2-)

Sulfite

HSO3 (-)

Hydrogen Sulfite

PO4 (3-)

Phosphate

HPO4 (3-)

Hydrogen Phosphate

H2PO4 (-)

Dihydrogen Phosphate

PO2 (3-)

Phosphite

CrO3 (2-)

Chromate

Cr2O2(2-)

Dichromate

MnO4 (-)

Permanganate

Naming Ionic Compounds with Polyatomic Ions - Write the name of the positive ion, usually a metal first - Write the name of the polyatomic ion last - Ex. Na2SO4 Sodium Sulphate

Section 5 -

Molecular Compound: contains two or more non metals that form a covalent bond - Valence electrons are shared by nonmetal atoms in covalent bonds to achieve stability - When two or more atoms share electrons, they form a molecule

Review Exam 2 -

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Prefixes are used to indicate the number of nonmetals. (nitrogen monoxide) In a hydrogen molecule (H2) - Two hydrogen atoms share electrons to form a covalent single bond - Each H atom acquires two (2) electrons - Each H becomes stable like the nearest noble gas, helium (He) Electron Dot Formula (Lewis Structure) - Shared electrons or bonding pairs are shown as two dots or a single line between atoms - Nonbonding pairs of electrons or lone pairs, are placed next to the atom - Electron Dot formulas for molecules with different elements show: - The order of the bonded atoms in a covalent compound - The bonding pairs of electrons between atoms - The unshared (lone) valence electrons - A central atom with an octet Diatomic Elements - Hydrogen - Nitrogen - Oxygen - Fluorine - Chlorine - Bromine - Iodine

Chapter 7 Section 1 -

A Mole (mol) is a unit that represents the same number of particles as there are carbon atoms in 12.01 g of carbon (Weight on the periodic table) Avagadro’s Number: 6.022 x 10^23

Section 2 -

Molar mass is: - The quantity of grams that equals the atomic mass of the element - The mass of one mole of an element or compound - The mass of 6.022 x 10^23 atoms of an element - The mass of 6.022 x 10^23 molecules or formula units

Section 3 -

The Molar Mass - Is a useful conversion factor - Converts moles of a substance to grams

Review Exam 2 -

Converts mass in grams of a substance to moles

Section 4 -

Given the mass of an element in a compound, we can calculate the mass percent composition of that element. The Mass Percent of an element in an compound: is the mass of an element divided by the total mass of the compound multiplied by 100%.

Section 5 -

Empirical Formula: represents the lowest whole number ratio of atoms in a compound. Molecular Formula: represents the actual number of atoms in a compound.

Chapter 8 Section 1 -

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Chemical Change: occurs when a substance is converted into one or more new substances. Chemical Reaction: - Involves chemical change - Represents the formation of a new substance with new properties Chemical Equation: tells us the materials needed and the products formed in a chemical reaction. - Reactants are written on the left, product on the right - Two or more formulas on one side are separated by a (+) sign - The delta sign, indicates heat is used to start the reaction - Physical states are abbreviated, including solid (s), liquid (l), gas (g), and aqueous (aq) Balance Equation: the atoms of each element are the same in the reactants and products.

Section 3 Chemical Equations - Combination - Two or more atoms form one product - Two or more simple compounds combine to form one product - Decomposition - One reactant splits into two or more simpler substances - Single Replacement - An uncombined element replaces an element in a compound - Double Replacement - Two elements in the reactants exchange places - Combustion

Review Exam 2 -

Carbon containing compounds, fuel burns in oxygen from the air to produce carbon dioxide, CO2, water, H2O, and heat or flame.

Chapter 9 Section 1 Law of Conservation of Mass: indicated that in an ordinary chemical reaction - Matter cannot be created nor destroyed - No change in total mass occurs in a reaction - Mass of products is equal to mass of reactants

Section 3 Limiting Reactant: in a chemical reaction is the substance that - Runs out first - Stops the reaction - Limits the amount of product that can form

Section 4 -

Theoretical yield: the amount of product we expect, if all the reactants were converted to the desired product Actual yield: the amount of product obtained when the reaction takes place Percent yield: the ratio of actual yield to theoretical yield

Section 5: The Heat of Reaction: - Is the amount of heat absorbed or released during a reaction at constant pressure - Is the difference in the energy of the reactants and the products Exothermic Reaction: - Heat is released - The sign is negative - The energy of the products is less than the energy of the reactants - Heat is a product Endothermic Reaction: - Heat is absorbed - The sign is positive - The energy of the products is greater than the energy of the reactants - Heat is a reactant Cation: +1 Anion: -1

Review Exam 2...