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Chem Exam II study guide

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o1234567889q's version from 2017-11-15 19:19

chap 4

Question Answer
what is aqueous solutiona solution in which the solvent is water and the solute initially is a liquid or a solid
what is an electrolytea substance that, when dissolved in water, results in a solution that can conduct electricity
difference between a strong and weak electrolyte equationstrong produces 100% dissociation while weak does not dissociate fully
what are the subcategories of strong electrolytesstrong bases, strong acids, salts
examples of strong basesNaOH, KOH, LiOH, Ba(OH)2, and Ca(OH)2
examples of strong acidsHCl, HBr, HI, HNO3, HClO3, HClO4, and H2SO4
examples of saltsNaCl, KBr, MgCl2, and many, many more
examples of weak acidsHF, HC2H3O2 (acetic acid), H2CO3 (carbonic acid), H3PO4 (phosphoric acid), and many more
examples of weak basesNH3 (ammonia), C5H5N (pyridine), and several more, all containing "N"
name for H2SO4sulfuric acid (strong acid)
C12H22O11sucrose (table sugar) (non electrolyte)
name for table saltNaCl (strong electrolyte)
AgClsilver chloride weak electrolyte
NH4ClAmmonium chloride strong electrolyte
when will a compound always ionize completelyanytime there is a soluble ionic compound
KOHpotassium hydroxide strong base
which group is always soluble which means they ionize completely and therefore are a strong electrolytegroup 1 (alkali metals)
Ba(OH)2barium hydroxide strong electrolyte
PbCl2lead 2 chloride weak electrolyte
most times when there is a compound w/ C, O, and H it will benon electrolyte
methanolCH3OH (non electrolyte)
C2H6Oethanol non electrolyte
CH3COOHacetic acid weak acid
NH3ammonia weak base
KNO3potassium nitrate strong electrolyte
always solublenitrates, alkali metals
C6H12O6glucose non electrolyte
what can be inferred from a compound w/ a nitrogen atomit may be a weak base
a compound which starts with H is probably aweak acid
a compound in the form metal(X)n is asalt
a compound in the form metal(OH)n is astrong base
what are the 7 strong acidshydrochloric acid: HCL, hydrobromic acid: HBr, Hydroiodic acid: HI, Nitric acid: HNO3, Perchloric acid: HClO4, Sulfuric acid: H2SO4, Chloric acid: HClO3.
what are all alkalisbases
weak acidsCH3COOH (acetic acid), HCOOH (formic acid), HF (hydrofluoric acid), HCN (hydrocyanic acid), HNO2 (nitrous acid), HSO4- (hydrogen sulfate ion)
strong basesNaOH sodium hydroxide, KOH potassium hydroxide, RbOH - rubidium hydroxide, CsOH - cesium hydroxide, Ca(OH)2 - calcium hydroxide, Sr(OH)2 - strontium hydroxide, Ba(OH)2 - barium hydroxide
weak basesNH3 ammonia, CH3NH2 methylamine, C5H5N pyridine
Spectator ions ions that are not involved in the overall reaction
How make net ionic equationscross out spectator ions from total ionic equation then rewrite
which equation shows the species as free ionsionic equation
what is a molecular equationequation that gives the formulas of compounds as though the species exist as molecules or whole units (has (aq) or (s))
how to write total ionic equationrewrite molecular in ions and include the (aq) or (s)
what is the name of the insoluble solid that separates from the solutionprecipitate
chemical formula for ethyleneC2H4
youtubeBalancing Complex/Difficult Chemical Equations Easily - Algebraic Method
how to find molar mass( mass of each atom X how many the atoms there are) > then add the results together
how to go from moles to gramshow many moles are given X molar mass of the substance
formula for percentage of mass of water in a salt(grams of water X 100)/hydrate: (grams of water + grams of salt)
slide solubility rules is on16
ionic equationshows the species as free ions
net ionic equationshows only the species that actually take part in the reaction
what state of matter is the precipitatesolid (s)
steps to write net ionic equationwrite the balanced molecular equation, refer to solubility table to decide which of the products is insoluble and thus will appear as a precipitate, write the ionic equation showing the strong electrolytes completely dissociated into cations and anions, cancel the spectator ions on both sides of the ionic equation, check that charges and number of atoms are balanced in the net ionic equation
what will the product of reaction ab+cd look likead+cb
what is the name of the salt we put on our friesNACL
what is a salt usually made up ofa nonmetal and a metal whose charges add up to zero
examples of liquids at standard temperature and pressureBr, H2O, Hg
examples of gases at standard temperature and pressure NH3, CH4, CO, CO2, SO2, SO3, NO, NO2 and N2O5
what is standard temperature and pressure25OC & 101.3 kPa
Halogens from top to bottomF, Cl, Br, I, At
halogen rules for single displacementonly the halogen above can displace a halogen. halogens cannot be displaced by halogens below them on the periodic table
what does a list called the activity series dodoes the same thing the periodic table does for halogens: it lists the elements that will replace elements below them in single-replacement
Activity Series for Cation Replacement in Single-Replacement ReactionsLi, K, Ba, Sr, Ca, Na, Mg, Al, Mn, Zn, Cr, Fe, Ni, Sn, Pb, H2, Cu, Hg, Ag, Pd, Pt, Au
what do Aqueous acid and base solutions both doconduct electricity
what do acids and bases do to plant dyescause color changes
characteristics of basesbitter, slippery, contained in many soaps
characteristics of acidssour, react with certain metals to form hydrogen gas, React with carbonates and bicarbonates to produce carbon dioxide gas
Arrhenius acida substance that produces H+ (H3O+) in water
Arrhenius basea substance that produces OH- in water
Brønsted acida proton donor
Brønsted basea proton acceptor
Hydronium ionhydrated proton, H3O+
Brønsted acid must containat least one ionizable proton
label the bronsted bases and acids in: NH3 + H2O > NH4+ + OH-base + acid > acid + base
examples of strong acidsHydrochloric acid … HCl, Hydrobromic acid … HBr, Hydroiodic acid … HI, Nitric acid … HNO3, Sulfuric acid … H2SO4, Perchloric acid … HClO4
examples of weak acidsHydrofluoric acid … HF, Nitrous acid … HNO2, Phosphoric acid … H3PO4, Acetic acid … CH3COOH
neutralization reactionArrhenius acid and base usually react to form water and a salt
which hydroxides are solublealkali metal hydroxides and Br(OH)2
Salts containing carbonates (CO32-), bicarbonates (HCO3-), sulfites (SO32-), and sulfides (S2-) react with acids to formgaseous products (CO2, SO2, and H2S)
decomposition reactiona type of chemical reaction in which a single compound breaks down into two or more elements or new compounds
what is an oxidation-reduction reaction also known as and what type of reaction is itredox reaction; is an electron-transfer reaction
what are the two half reactions of Oxidation-reduction reactionsoxidation half-reaction and reduction half-reaction
oxidation half-reactionloss of electrons (reactant is broken down into reactant + electron in the product)
reduction half-reactiongains electrons (the electron is added to reactant which makes the product)
the reducing agent is oxidized by giving electron whilethe oxidizing agent is reduced reduced by receiving electron
Common oxidizing agents includeoxygen, hydrogen peroxide and halogens
what does oxidation number indicateif electrons are lost or gained
what do solubility rules need to be known forprecipitation reactions
what do oxidation number rules need to be known forredox reactions
when is oxygen's oxidation number in its compounds not -2in peroxides, in this case its number is -1. If its bound to fluorine: +1
when is hydrogen's oxidation number -1 instead of +1when it's in a binary metal hydride
which method is used to balance redox reactionsthe half equation method
3 conditions to determine when balancing redox reactionsneutral, basic, and acidic conditions
look over balancing redox reactions @https://chem.libretexts.org/Core/Analytical_Chemistry/Electrochemistry/Redox_Chemistry/Balancing_Redox_reactions
oxidation numberThe charge the atom would have in a molecule (or an ionic compound) if electrons were completely transferred
Oxidation number of oxygen in the superoxide ion, O2--1/2
__________ elements have only positive oxidation numbers, whereas _________ elements may have either positive or negative numbersMetallic …. Nonmetallic
Redox reactions can be subclassified asCombination, Decomposition, Combustion, Displacement, Disproportionation reaction
Combination reactiona reaction in which two or more substances combine to form a single product
Decomposition reactionthe breakdown of a compound into two or more components
Combustion reaction a reaction in which a substance reacts with O2, usually with the release of heat and light to produce a flame
Displacement reactiona reaction in which an ion (or atom) in a compound is replaced by an ion (or atom) of another element
know activity series of metals and halogensfile:///home/chronos/u-8cd3e2b04ff51ae598c7cb5ed7efc75ac744ac0c/Downloads/2a_-_activity_series.pdf
activity seriesatoms above displace ones below. bottom ones cannot displace top ones in reactions
Disproportionation Reactiona reaction in which an element in one oxidation state is simultaneously oxidized and reduced
how to identify a precipitation reactionusing solubility rules
What is the requirement for an element to undergo disproportionation reactionsthe element must have at least three oxidation states
molarity formulam equals moles of solute/ liters of solution (n/v) (mol/L)
moles to mass (g) multiply molar mass of the substance by how many moles are given in the problem
What mass of KI is required to make 500. mL of a 2.80 M KI solution500. mL x 1L/1000mL x 2.80M/1 L sol x 166g KI/ 1mol KI equals 232 g KI
make link with screenshot of slide77
what does the abbreviation for molarity: M stand formol/L
g to molesgrams/molecularweight
mol to gmolar mass x moles
molM x V (molarity times volume)
dilution equationM1 V1 equals M2 V2
when a problem is asking for concentration of a solution, what is it asking forM
nM x v 8:02
formula to use when finding m of a diluted solutionM1V1 equals M2V2
https://www.youtube.com/watch?v=-4E6rOkiw2I26:46
charge of sulfate (SO4)-2
units for molecular weight (MW)g/mol
Mn/V
Vn/M
when using m1v1 equation what has to be volumeliters not ml
Gravimetric Analysisan analytical technique based on the measurement of mass
steps of gravimetric analysisDissolve unknown substance in water, React unknown with known substance to form a precipitate, Filter and dry precipitate, Weigh precipitate, Use chemical formula and mass of precipitate to determine amount of unknown ion
what occurs In a titrationa solution of accurately known concentration is added gradually to another solution of unknown concentration until the chemical reaction between the two solutions is complete
Just like an acid can be titrated against a basean oxidizing agent can be titrated against a reducing agent
molarity equationmolarity=moles of solute/liters of solution
memorize

Chap 5

Question Answer
what are normal atmosphere conditions1 atm and 25 degrees C
by volume, what is air composed of78% N2, 21% O2, 1% other gases including CO2
what is SI unit for pressurepa (pascal)
how many pa in 1 atm1 atm is 1.01325 x 105 Pa
Elements that exist as gases at 25oC and 1 atmosphereH2, N2, O2, F2 and Cl2 exist as gaseous diatomic molecules, He, Ne, Ar, Kr, Xe, and Rn are monatomic gases
what makes it less likely the compound can exist as a gas at ordinary temperatureit is less likely the stronger the intermolecular forces
what are solids rather than gases under atmospheric conditionsionic compounds
know compounds and elements that exist as gases at room temperaturess
pressureforce/area
forcemass x acceleration
units for pressure=force/area=mass x acceleration/areapa=N/m^2, force=kg x m/s^2 (mass x acceleration)
Atmospheric pressurethe pressure exerted by Earth’s atmosphere
The density of air decreases withincreasing distance from Earth
The denser the air,the greater the pressure
the most common instrument for measuring atmospheric pressurebarometer
Standard Atmospheric pressure (1 atm) is equal tothe pressure that supports a column of mercury exactly 760 mm high at 0oC at sea level
mmhgmillimeter of mercury
1 atm760mmhg=760 torr=101,325pa
manometerused to measure the pressure of gases
what relationship is boyle's law aboutpressure volume relationship
Boyle’s Law states thatthe pressure of a fixed amount of gas at a constant temperature is inversely proportional to the volume of the gas P=1/v
equation for constant in boyles lawPxV=constant
equation for pressure volume relationshipP1V1=P2V2 means constant temperature=constant amount of gas
law for Temperature-Volume RelationshipCharles’s and Gay-Lussac’s Law
memorize
Charles’s Law states that the volume of a fixed amount of gas at a constant pressure is directly proportional to the absolute temperature of the gas
Question Answer
know Charles’s & Gay-Lussac’s Law: Graphical Representationss
unit for T in charles lawkelvin
c to kc + 273.15
f to kT(K)=(T(°F) + 459.67)× 5/9
c to fT(°F)=T(°C) × 1.8 + 32
f to c(T(°F) - 32) / 1.8
avogadro's lawV1n1=V2n2
Avogadro's law, a statement thatunder the same conditions of temperature and pressure, equal volumes of different gases contain an equal number of molecules
memorize
ideal gas equation PV=nRT
Question Answer
density equationsd=m/V=PM/RT m is mass M is molar mass of the gas
molar mass of gas equationM=dRT/P d is density of gas in g/L
memorize