Chemistry Fall Final Study Guide Concepts



Chemistry Fall Final Review 2012-2013Alchemy Unit Using the periodic table, where are the metals and nonmetals? What is hydrogen?Metals are in the left side of the periodic table. Nonmetals are on the right side of the periodic table. Hydrogen is an nonmetal. Where are the alkali, alkaline earth, transition metals, halogens, and noble gases?Alkali metals = group 1, alkaline earth metals = group 2, transition metals = middle of periodic table, halogens = group 7, and noble gas = group 8On the periodic table, what are the trends for atomic mass, atomic number, atomic radii(size), and reactivity as you move across a period and down a group? On the periodic table: Atomic mass increases from left to right and top to bottomAtomic numbers increase from left to right and top to bottomAtomic radii increases from top to bottom and right to leftReactivity: Metals increase from top to bottomNonmetal increases from bottom to top Draw a Bohr atomic model of lithium. Label the parts of the atom and their charges. Nucleus is in the center and contains the protons (positive charges) and neutrons (neutral). Electrons are negatively charged and they on the two shells. a).Which part of the atom is the heaviest and lightest?The nucleus is the heaviest part of the atom. The electrons are the lightest in weight. What is the atomic number and atomic mass of phosphorus and strontium?P: atomic number =15, atomic mass = 30.97 amuSr: atomic # = 38, atomic mass = 87.62 amua). What is the difference between atomic number and atomic mass?Atomic number is the number of protons. Atomic mass is the weight of an atom (protons plus neutrons). What is an isotope? Name two possible isotopes for carbon and potassium.An isotope is atom that can have different number of neutrons. Carbon -12 and Carbon-13; Potassium-39 and Potassium-40a). Write the equation for the alpha decay of astatine -213. b). Write the equation for the beta decay of neptunium -239.c) What is more harmful alpha particles, beta particles, or gamma rays?213 85As→ 42 He + 209 83 Bi239 93 Np →239 94 Pu + 0 -1 e Gamma rays are the most harmful then beta particles and finally alpha particles. What are valence electrons? Which subshells are included in valence?Valence electrons are the electrons on an atom’s outer shell. Valence electrons are on the s and p subshells. How many valence electrons do Mg, S, and Al have? Mg = 2, S=6, Al=3What elements have the following electron configurations of a). 1s22s22p63s23p64s23d104p1Gallium b). 1s22s22p63s23p4SulfurFill in table.Type of BondConducts Electricity? Dissolves in water? Conducts electricity when dissolved?Metals Metallic YesNoMetal and NonmetalIonicNoYesYesNonmetals (hard solids)Covalent NetworkNoNoNonmetals (l, g, soft solids)Molecular CovalentYesYesNo What are ions? What are cations and anions?Ions are atoms that have lost or gain electrons and become positive or negative charged. Cation is a positive ion and an anion is a negative ion. In ionic bonds, metals tend to lose electrons and nonmetals gain electrons. What happens to these elements to achieve noble electron configuration? What charge does the element form?a). oxygen Gain 2 electrons and become O-2b). chlorine Gain 1 electron and become Cl-1c). sodium Lose 1 electron and become Na+1 d). bariumLose 2 electrons and become Ba+2a). What is the chemical formula and name of the compound formed when beryllium reacts with fluorine? b). What is the chemical formula and name of the compound formed when when potassium reacts with sulfur? Be will lose 2 electrons and F will gain 1 electron. Be+2 and F-1 will crisscross charges and form BeF2, beryllium fluoride. K will lose 1 electron and S will gain 2 electrons. K+1 and S-2 will crisscross charges to form K2S, potassium sulfide. What are the chemical formula and charge for the following polyatomic ions? a). sulfate b) hydroxide c) nitrate OH -1hydroxideSO4 -2sulfateNO3 -1nitrateSmells UnitWhat are isomers? Draw the three isomers for C3H9N.An isomer is when a molecule has the same molecular formula but different structural formulas. Any three of the structures below are correct. 51600719078What is the HONC1234 and Octet rule? Which molecules obey the Octet rule? Draw the Lewis Dot structures for the following molecules. a). CF3 b). PCl2 c). OCl2 d). SiI4 HONC1234 rules states that hydrogen bonds once, oxygen bonds twice, nitrogen bonds three times, and carbon bonds four times. The octet rules states that elements need to obtain eight valence electrons through bonding to be stable. Only c and d obey the octet rules.1987553238500 .. :I: .. .. .. .. .. ..:I:Si:I::Cl:O:Cl: ˙˙˙˙ ˙˙ ˙˙ ˙˙ ˙˙ :I: ˙˙What are the different functional groups, the smells associated for each, and their common names endings?Functional GroupStructure Smell Name endingsEster O=C-O-CSweet“-ate”Carboxylic AcidO=C-O-HPutrid “-acid”Ketone O=CMinty “-one”AlcoholC-O-HCamphor, Minty, Sweet“-ol”Amine C-NFishy “-amine”What is an electron domain? What is the difference between lone pairs and bonded electron pairs?Electron domains are set of electrons (bonded or lone) that surround an atom. Lone pairs are electrons that are from the same atom. Bonded pair are electrons that from two different atoms in a bond. Fill in table. MoleculeLewis Dot StructureStructural Formula and Name of Shape Lone pairs on central atomBonded pairsCO2 .. .. :O::C::O:O=C=O Linear04SeCl2 .. .. .. :Cl:Se:Cl: ˙˙ ˙˙ ˙˙ Se Bent / \ Cl Cl22NH3 .. H:N:H ˙˙ H N Pyramidal / | \ H H H13CH4 H .. H:C:H ˙˙ H H Tetrahedral | C / | \ H H H04CH2O H .. .. H:C::O: O Trigonal || Planar C / \ H H04What is a catalyst? What does it do? A catalyst is a substance that is not a reactant or product but added to a reaction to accelerate the reaction time.Write the molecular formula, structural formula, Lewis Dot structure, and ball-and-stick formula for water. Molecular formula H2OStructural Formula Lewis Dot Structure Ball and Stick Model What are the different characteristics between a polar vs. nonpolar molecules? (ex: dissolve in water, attraction to a negatively charged wand, on wax paper).Polar Molecules Nonpolar Molecules Partial chargesNo chargeDissolve in water Does not dissolve in waterAttract to charged wandNo attract to charged wandBead up (droplet) Spreads out Smells Does not smell How do you use the electronegativity values chart to determine nonpolar covalent, polar covalent, and ionic bonds? What is happening to the electrons in these different bonds?Nonpolar covalent bonds have electronegativity difference between 0-0.3 and there is equal sharing of electrons. Polar covalent bonds have ED between 0.4-1.8 and there is unequally sharing of electrons.Ionic bonds have ED 1.9 or higher and there is losing and gaining of electrons. Determine type of bond between these atoms: Cl-Cl, As-H, Ca-O, P-I, K-Cl, and Si-FCl-Cl3.16-3.16=0 Nonpolar covalent bondAs-H 2.18-2.10=0.08Nonpolar covalent bondO-Ca3.44-1.00=2.44Ionic bondI-P2.66-2.19=0.47Polar covalentCl-K3.16-0.82=2.34Ionic bondF-Si 3.98-1.90= 2.08Polar covalent (not ionic because the two elements are nonmetals)Are the following molecules polar or nonpolar molecules? Explain a). SiF4 b). PI3 a). SiF4 is nonpolar. The bonding between Si and F is polar covalent. The tetrahedral shape of the molecule is symmetrical which cancels out the partial charges. The resulting molecule is nonpolar. b). PI3 is polar. The bond between P and I is polar covalent. The pyramidal shape of the molecule is not symmetrical so the partial charges remain to result in a polar molecule. What are van der Waals forces: hydrogen bonding, dipole-dipole forces, and London Dispersion forces?Hydrogen bonding is the way polar molecules that contain hydrogen stick together. Specifically, hydrogen in a molecule is partially positive is attracted to the partially negative atom (F, O, N) in another molecule. Hydrogen bonding is illustrated with the dash lines.Dipole-dipole forces are the way polar molecules stick together. Like hydrogen bonding, the partial positive end attracts to the partial negative end of another molecule.London dispersion forces are the way nonpolar molecules stick together. Nonpolar molecules have temporary dipoles which create temporary partial negative and positive ends. These temporary charges attract to each other. ................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download