AP Chemistry Flashcards

13721359020	Avogadro's number	6.02 x 10^23	0
13721361482	Ideal Gas Law	PV=nRT P = pressure V = volume n = moles of gas R = gas constant: .0821 Latm/molK T = temperature (K)	1
13721375558	STP	P = 1 atm T = 273K 1 mole = 22.4 L	2
13721384512	Percent Composition	the percent by mass of each element in a compound mass of element/total molar mass of the substance	3
13721405305	Empirical Formula	a formula with the lowest whole-number ratio of elements in a compound 1) assume 100 gram sample (percentage-->gram) 2) convert the gram amount to mol of element 3) take the lowest mol amount and divide each number by that value 4) round to the nearest whole number 5) these values become the subscript	4
13721432840	Molecular Formula	A chemical formula that shows the number and kinds of atoms in a molecule, but not the arrangement of the atoms. 1) find molar mass of the empirical formula 2) molar mass of MF/molar mass of EF 3) multiply all the subscript in the empirical formula by that value	5
13721466372	Aufbau Principle	the rule that electrons occupy the orbitals of lowest energy first	6
13721470194	Pauli Exclusion Principle	states that a maximum of two electrons can occupy a single atomic orbital but only if the electrons have opposite spins	7
13721474793	Hund's Rule	states that single electrons with the same spin must occupy each equal-energy orbital before additional electrons with opposite spins can occupy the same orbitals	8
13721486107	Coulomb's Law	E=kq1q2/r^2 E = energy k = Coulombs Constant: 8.98810^9 Nm^2/C^2 q1 (+) = magnitude of the positive charge (nucleus) q2 (-) = magnitude of the negative charge (electron) r = distance between the charges the greater charge of the nucleus the more energy an electron will have	9
13721523183	Quantum Theory	describes mathematically the wave properties of electrons and other very small particles quantum: E = hv	10
13721535493	The Bohr model	model of the atom in which electrons move rapidly around the nucleus in paths called orbits * the closer the energy level is to the atom the less energy electrons that level has	11
13730998731	Energy and Electromagnetic Radiation	△E = hv = hc/λ △E = energy change h = planck's constant: 6.63x10^-34 joulesec v = frequency of radiation λ = wavelength of radiation c = speed of light: 3.00x10^8 m/sec high frequency and shorter wavelength lead to more energy	12
13731022520	Frequency and Wavelength	c = λv c = speed of light: 3.00x10^8 m/sec λ = wavelength of radiation v = frequency of radiation	13
13731032861	Ionization Energy	The amount of energy required to remove an electron from an atom	14
13731039833	Photoelectron Spectroscopy (PES)	energy measurement of electrons emitted from solids, gases or liquids by the photoelectric effect, in order to determine the binding energies of electrons in a substance *decreases from left to right	15
13731051094	Electron Configuration	the arrangement of electrons in the orbitals of an atom	16
13731053673	Dalton's Atomic Theory	1) elements are composed of atoms. 2) atoms of same element are identical, but differ from other elements. 3) elements can mix together 4) atoms only change when mixed with other elements	17
13731061952	J.J. Thomson's Model	Plum pudding model *atoms are composed of positive and negative charges. negative charges are called electrons and they are sprinkled throughout the positively charged atom	18
13731068832	Ernest Rutherford	Gold foil experiment *positive charge in an atom is concentrated in the center and the atom is mostly empty space...positive charged nucleus (mass) and negatively charged electrons travel around the nucleus	19
13731076991	Heisenberg Uncertainty Principle	it is impossible to know exactly both the velocity and the position of a particle at the same time	20
13731079184	Periodic Trend: Atomic Radius	increases left and down increases left less protons so weaker attraction increases down because more electrons are added to the electron shells	21
13731323455	Periodic Trend: Ionization Energy	increase right and up increases to the right because more protons so stronger attraction increases up because less shielding so more attraction	22
13731328515	Periodic Trend: Electronegativity	increases right and up increases to the right because more protons so stronger attraction increases up because less shielding so more attraction	23
13731332983	Periodic Trend: Electron Affinity	increases right and up *energy releases or absorbed when the electron is added in th eatom	24
13731333698	Periodic Trend:Ionic Radius	increase left and down *more electrons the larger the radius	25
13734711391	Isoelectronic	having the same number of electrons *largest will be element with less protons	26
13734736525	Exception for Ionization Energy	Between Be B and N and O further away more shielding so less attraction O has to electrons in one orbital so there electron-electron repulsion	27
13737927533	Bonding	transfer or sharing of electrons	28
13737930749	Ionic Bonds	the electrostatic forces that hold ions together in ionic compounds metal and none metal (electrons are NOT shared) cation--gives up and electron and becomes positively charged anion--accepts and electron and becomes negatively charged solid at room temp and have high MP and BP	29
13737964300	Lattice Energy	the energy required to separate 1 mol of the ions of an ionic compound greater charge = greater lattice energy = high MP small ion(radius) = high MP	30
13737980777	Metallic Bonds	a bond formed by the attraction between positively charged metal ions and the electrons around them *malleable, ductile, good conductors of electricity	31
13737990469	Interstitial Alloy	an alloy whose component atoms are different sizes	32
13737993106	Substitutional Alloy	an alloy whose component atoms are similar in size	33
13737997558	Covalent Bonds	bonds created by sharing electrons with other atoms first covalent bond between two atoms is called a sigma (σ) bond and additional bonds are called pi (π) bonds double and triple bonds are stronger and shorter than single bonds	34
13738029893	Network Covalent Bonds	atoms held together in lattice of covalent bonds (diamond); hard with high melting point	35
13738077503	Polarity	molecules having an uneven distribution of charges *the most electronegative atoms exerts the most pull	36
13738115509	Intermolecular Forces	forces that exist between molecules in a covalently bonded substance need to be broken to change phases when ionic substances change phase the bonds between the individual ions are broken *when covalent substances change phase the bonds between the individual atoms remain but the forces that hold the molecules to other molecules breaks	37
13740188728	Dipole-Dipole Forces	forces of attraction between polar molecules molecules with greater polarity will have a greater dipole moment--higher MP and BP relatively weak and low MP and BP	38
13740197766	Hydrogen Bonds	a special type of dipole-dipole moment. positive hydrogen atom attracted to negatively charged element (NOF)	39
13740204904	London Dispersion Forces	occur between all molecules. the intermolecular attractions resulting from the constant motion of electrons and the creation of instantaneous dipoles. *since LD depends on the random motion of electrons--more electrons = more LD	40
13740219835	Bond Strength	ionic--solids at room temp covalent--liquids at room temp (low MP and BP) metallic--often involves one type of atom, very strong(high MP and BP) network covalent--strongest type of bonding so extremely difficult to melt	41
13740232060	Bonding and Phases	phase of a substance if directly related to the strength of its IMF. weak IMF=gas at room temp. strong IMF=liquid at room temp. ionic substances do no experience IMF (phase determined by ionic bonding (STRONG))=solid at room temp. solids--packed together liquid--loose gas--spread apart	42
13740255873	Vapor Pressure	molecules within a liquid are in constant motion but if the molecules hit the surface with enough KE they can break their IMF and become gas. strong IMF=low vapor pressure bc of high temp required	43
13740266672	Lewis Dot Structure	diagram of a molecule using dots to represent valence electrons	44
13740270315	Resonance Structure	one of the two or more equally valid electron dot structures of a molecule or polyatomic ion	45
13740273232	Bond Order		46
13740283098	Incomplete Octet	These elements are stable with fewer than eight electrons in their valence shell and include hydrogen (2), helium (2), lithium (2), beryllium (4), and boron (6).	47
13740282163	Expanded Octet	An exception to the octet rule that permits atoms in d block or lower on the periodic table to have more than eight electrons in a Lewis structure.	48
13740329788	Formal Charge	used to determine which resonance structure is more likely. # of valence electrons - ( # lone pairs + # bonds) (each lone pair is 2 and each bond is one) charges should at up to total molecule charge the most electronegative element should possess the negative charge if there is one	49
13740355089	Molecular Geometry	electrons repel each other so when atoms come together they will assume a shape that keeps its electron pairs far apart valence shell electron-pair repulsion (VESPR) double and triple bonds are treated the same way as a single bond when predicting molecular geometry *molecules with lone pairs will have reduced angles	50
13740379837	Hybridization: 2 electron pairs	sp	51
13740379838	Hybridization: 3 electron pairs	sp^2	52
13740381627	Hybridization: 4 electron pairs	sp^3	53
13740382346	Hybridization: 5 electron pairs	dsp^3	54
13740383346	Hybridization: 6 electron pairs	d^2sp^3	55
13740383863	Kinetic Molecular Theory	based on the idea that particles of matter are always in motion *the greater the temperature the greater average kinetic energy of gas molecules	56
13740391171	The Average Kinetic Energy of a Single Gas Molecule	KE = 1/2 mv^2 or v = √(3RT)/(m) KE = kinetic energy m = mass v = volume R = gas constant (.0821) T = temperature	57
13740456007	Maxwell-Botzmann Diagrams	a diagram that shows the range of velocities for molecules of a gas. molecules at a given temperature are not all moving at the same velocity *higher temperature of gas-->larger range for velocity (higher KE)	58
13740803354	Boyle's Law	P1V1=P2V2	59
13740803355	Charles Law	V1/T1=V2/T2	60
13740806620	Combined Gas Law	P1V1/T1=P2V2/T2	61
13740807089	Gay-Lussac's Law	P1/T1=P2/T2	62
13740807959	Dalton's Law	total pressure of a mixture of gases is just the sum of all the partial pressure P total=P1+P2+P3...	63
13740812947	Partial Pressure	Pa = (P total)(Xa) Xa = (moles of gas A/total moles of gas)	64
13740816971	Density	D = m/v D = density m = mass of gas in grams v = volume occupied by gas in liters D = P(MM)/RT MM = D(RT)/P	65
13740824089	Molarity	expresses the concentration of a solution in terms of volume. the number of moles of solute per liter of solution M = moles of solute/liters of solution	66
13740827809	Mole Fraction	The ratio of the moles of solute in solution to the total number of moles of both solvent and solute Mole Fraction (X) = moles of substance S/total number of moles in the solution	67
13740829581	Solutes and Solvents	LIKE DISSOLVES LIKE AKA polar or ionic solutes like salt will dissolve in polar solvents like water. non polar dissolves non polar.	68
13740831182	Dissociation	the separation of ions that occurs when an ionic compound dissolves	69
13740832566	Paper Chromatography	method of separating a mixture of different colors. The liquid soaks through the paper and carries the mixture with it. Some substances are carried faster than others so the substances are separated along the paper	70