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44 Cards in this Set
- Front
- Back
- 3rd side (hint)
Allotropes
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different structural modifications of an element; the atoms of the element are bonded together in a different manner.
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graphite & diamond
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Law of Definite Proportions
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states that a chemical compound always contains exactly the same proportion of elements by mass.
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sometimes called Proust's Law; fundamental law of stoichiometry
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Law of Multiple Proportions
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states that if two elements form more than one compound between them, then the ratios of the masses of the second element which combine with a fixed mass of the first element will be ratios of small whole numbers
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sometimes called Dalton's Law; fundamental law of stoichiometry
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Law of Conservation of Mass
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states that the mass of an isolated/closed system will remain constant over time.
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principle is equivalent to the conservation of energy; fundamental law of stoichiometry
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Stoichiometry
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a branch of chemistry that deals with the relative quantities of reactants and products in chemical reactions.
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Reaction Stoichiometry
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describes the quantitative relationships among substances as they participate in chemical reactions.
In the hint, this describes the 1:3:2 ratio of molecules of nitrogen, hydrogen, and ammonia. |
N2 + 3H2 → 2NH3
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Composition Stoichiometry
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describes the quantitative (mass) relationships among elements in compounds.
In the hint, this describes the nitrogen to hydrogen ratio in the compound ammonia: 1 mol of ammonia consists of 1 mol of nitrogen and 3 mol of hydrogen. As the nitrogen atom is about 14 times heavier than the hydrogen atom, the mass ratio is 14:3, thus 17 kg of ammonia contains 14 kg of nitrogen and 3 kg of hydrogen. |
N2 + 3H2 → 2NH3
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Gas Stoichiometry
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deals with reactions involving gases, where the gases are at a known temperature, pressure, and volume, and can be assumed to be ideal gases. For gases, the volume ratio is ideally the same by the ideal gas law, but the mass ratio of a single reaction has to be calculated from the molecular masses of the reactants and products. In practice, due to the existence of isotopes, molar masses are used instead when calculating the mass ratio.
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N2 + 3H2 --> 2NH3
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Limiting Reactant
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The reactant that is used up completely in the reaction
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Solution
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The solute dissolved in the solvent
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Titration
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a common laboratory method of quantitative chemical analysis that is used to determine the unknown concentration of an identified analyte
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Also known as volumetric analysis
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Equivalence Point
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in a chemical reaction, the point at which an added titrant is stoichiometrically equal to the number of moles of substance (known as analyte) present in the sample: the smallest amount of titrant that is sufficient to fully neutralize or react with the analyte.
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coincides with an endpoint, an indicator color will cahnge
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Solvent
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a substance that dissolves a solute
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more concentrated than solute; water is the universal solvent
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Solute
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a substance dissolved in a solvent
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less concentrated than the solvent
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Periodic Law
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in chemistry, law stating that many of the physical and chemical properties of the elements tend to recur in a systematic manner with increasing atomic number.
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The chemical law that the properties of all the elements are periodic functions of their atomic weights was developed independently by two chemists: in 1869 by Dmitry Mendeleyev, a Russian, and in 1870 by Julius Lothar Meyer, of Germany. The key to the success of their efforts was the realization that previous attempts had failed because a number of elements were as yet undiscovered and that vacant places must be left for such elements in the classification.
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Metals
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high conductivity, high thermal conductivity, malleable, few electrons in outer shell, metallic character increases as you go down and left on periodic table
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all but mercury are solid(Ce and Ga melt), gray except AG and AU
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Electrolytes
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substances whose aqueous solutions conduct electricity well, includes strong acids, strong soluble bases, most soluble salts
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Precipitates
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the formation of a solid in a solution or inside another solid during a chemical reaction or by diffusion in a solid.
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Oxidation number
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the charge that it would have if all the ligands were removed along with the electron pairs that were shared with the central atom.
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The oxidation number of an element in its elementary form is zero. For example, hydrogen, oxygen, nitrogen, chlorine, phosphorus, sulphur, copper, iron etc. have oxidation number equal to zero.
The sum of the oxidation numbers of all the atoms in an ion or molecule is its net charge. In compounds with non-metals, the oxidation number of hydrogen is +1. However, when hydrogen is compounded with a metal, its oxidation number reduces to −1 (the metal being a more electropositive element). Oxygen has been assigned oxidation number of −2 in its compounds. However, there are certain exceptions also. In peroxides such as hydrogen peroxide, the oxidation number of oxygen is −1. In oxygen difluoride the oxidation number of oxygen is +2 while in dioxygen difluoride, oxygen is assigned an oxidation number +1 (fluorine being a more electronegative element). The atom with higher electronegativity, typically a nonmetallic element, is assigned negative oxidation number while the other atom, often a metallic element, is given positive oxidation number. |
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Oxidation
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loss of electrons
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Reduction
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gain of electrons
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Oxoacids
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an acid that has the elements hydrogen and oxygen along with another element, often a nonmetal. Equivalently, they contain hydrogen in addition to a polyatomic ion.
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also called a ternary acid
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Ligand
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an ion or molecule (functional group) that binds to a central metal atom to form a coordination complex
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Photoelectric effect
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x
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Heisenberg Uncertainty Principle
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You cannot know both momentum & position of an electron
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Aufbau Principle
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x
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Pauli Exclusion Principle
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x
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Hund's Rule
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x
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Paramagnetic
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x
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Diamagnetic
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x
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Ferromagnetic
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x
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Combustion reaction
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oxygen combines rapidly, very exothermic, hydrocarbon+oxygen yields carbon dioxide, water and heat
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Roasting
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extracting free metals by heating an ore in air(oxygen)
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Ionic compounds
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high melting point, soluble in polar solvents, insoluble in nonpolars, molten and aqueous solutions conduct electricity; large electronegativity difference between atoms
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Lewis dot formulas
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show valence electrons
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Octet Rule
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most compounds achieve noble gas configurations
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Resonance
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two or more Lewis structures describe bonding
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Formal Charge
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charge on atom in a molecule or polyatomic ion
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Polar covalent bond
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electrons shared unequally; creates dipole
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Sigma bond
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x
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Pi bond
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x
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dipole
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x
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molecular orbital
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an orbital resulting from overlap and mixing of atomic orbitals of different atoms; belongs to a molecule as a whole
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Antibonding orbital
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molecular orbital higher in energy than any of atomic orbitals from which it is derived; lends stability when populated; marked with an asterisk
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