# Shared Flashcard Set

## Details

Chemistry TCB Exam Flashcards
Cards to help you study for the testing out exam on June 3
97
Chemistry
05/17/2011

Term
 chemistry =
Definition
 study of substances and the changes they undergo
Term
 Describe the Atlantic/Pacific rule.
Definition
 decimal Absent: start on the Atlantic side of the number, count the first non-zero number and all that follow decimal Present: start on Pacific side of the number, count the first non-zero number and count all that follow
Term
 How many sig figs do I use when measuring things in lab situations?  (ex. graduated cylinder or ruler)
Definition
 go to the nearest line given, then estimate one decimal past that (if a graduated cylinder shows lines every 1mL, your answer should be to the nearest 1/10mL  ex. 10.5mL)
Term
 accuracy
Definition
 how close a measurement is to the real answer
Term
 precision
Definition
 how close a measurement is to other measurements
Term
 How many sig figs in: 7.2340 0.03460 1,340.01
Definition
 5 4 6
Term
 How do we measure density?
Definition
 mass/volume
Term
 Put the following in scientific notation: 5,245,252 0.00346
Definition
 5.25x10^6 3.46x10^-3
Term
 If I shoot my bow, and I consistently hit low and to the left, are my shots precise or accurate or both?
Definition
 precise (the shots are consistent, but not accurate, that is, they're not close to the bullseye)
Term
 Convert the following: 1,288 inches = ____? meters 2.54cm / inch
Definition
 3,271.52cm or 3,270cm (3 sig figs)
Term
 independent variable
Definition
 the thing I change/control
Term
 dependent variable(s)
Definition
 the thing(s) you measure
Term
 law of conservation of energy
Definition
 energy is neither created or destroyed
Term
 law of conservation of mass
Definition
 mass is neither created or destroyed
Term
 law of conservation of matter
Definition
 matter is neither created or destroyed
Term
 Which can NOT be broken down any further? sodium, disulfate, diatomic oxygen, hydroxide
Definition
 sodium, because its an element.  The rest are either molecules or compounds
Term
 Is a phase change a chemical change or a physical change?
Definition
 Physical change because its only changing forms, not creating something new
Term
 chemical change
Definition
 when a chemical reaction takes place and new products are formed
Term
 Which state of matter is typically the LEAST dense?
Definition
 Gas
Term
 What is an alpha particle?
Definition
 a helium nucleus (2 protons, 2 neutrons)
Term
 How do you balance nuclear equations?
Definition
 balance the top number (mass number) and balance the bottom number (atomic number)
Term
 If the result of a nuclear equation is a particle with a mass number of 4 and atomic number of 2, what type of nuclear reaction happened?
Definition
 alpha decay, because an alpha particle has an atomic # of 2 and mass # of 4.
Term
 If the result of a nuclear equation is a particle with a mass number of 0 and atomic number of -1, what type of nuclear reaction happened?
Definition
 beta decay, because the result of beta decay is the decay of a neutron into a proton and the release of an electron
Term
 Match the scientist: Bohr                   gold foil experiment JJ Thomson        planet model of atom Rutherford                      plum pudding
Definition
 Bohr:  planetary model Thomson:  plum pudding Rutherford:  gold foil
Term
 What did the gold foil experiment done by Rutherford prove?
Definition
 atoms have very tiny, but very dense nuclei
Term
 If I started with 48g of Carbon-12, and 1yr later I have 38g, what term describes what has happened?
Definition
Term
 If the half-life of carbon-12 is 5.73yrs, and I started with 100g, how much is left after 11.46yrs?
Definition
 25 grams because 11.46yrs is 2 half-lives 100g-->50g-->25g
Term
 How many half-lives does it take to have 1/16 of the original sample left?
Definition
 4 half-lives 1-->1/2-->1/4-->1/8-->1/16
Term
 If the mass number of element X is 48, and it has 22 protons, how many neutrons does it have?
Definition
 26 neutrons 48 - 22 = 26
Term
 If the atomic number of element X is 43 and it contains 41 electrons, what is the ion charge?
Definition
 +2
Term
 What does the neutron do for an atom?
Definition
 Three important things: 1.  it supplies the force that holds the nucleus together 2.  it makes the atom more stable 3.  it is the "glue" of the nucleus
Term
 What is the atomic mass of element X: isotope 1: 18.32amu, abundance 21.30% isotope 2: 19.27amu, abundance 70.20% isotope 3: 20.11amu, abundance 8.50%
Definition
 19.14amu 18.32 x .2130 = 3.90 19.27 x .7020 = 13.53 20.11 x .0850 = 1.71
Term
 electrons have several energy levels, which contain _____, which contain _______ that each hold a pair of electrons.
Definition
 sublevels orbitals
Term
 s, p, d and f describe what?
Definition
 electron sublevels (and areas on the periodic table that contain those sublevels)
Term
 What is the shape of the s-sublevel?
Definition
 sphere
Term
 What is the shape of the p-sublevel?
Definition
 dumb bell shape
Term
 How many valence electrons do the following have? Na, C, Ne
Definition
 Na = 1 C = 6 Ne = 8
Term
 What element has the same electron configuration as Al+3?
Definition
 Neon because aluminum lost 3 electrons, giving it the same configuration as the element with 3 less electrons
Term
 If we vaporize an element in a flame, what type of light is given off?
Definition
 only specific wavelengths of light, which are based on the energy given off by the electrons as they fall back to their "ground state"
Term
 What color of light has the highest energy? lowest?
Definition
 highest: violet lowest: red
Term
 What is the electron configuration for Fe (iron)?
Definition
 1s2, 2s2, 2p6, 3s2, 3p6, 4s2, 3d8
Term
 Why are valence electrons important?
Definition
 they are the electrons involved in reactions and bonding
Term
 What halogen has the highest ionization energy? Why?
Definition
 Fluorine because its outermost electron is closest to the nucleus
Term
 ionization energy
Definition
 energy needed to "pluck" an electron from an atom;  increases as you go right and up on the periodic table
Term
 Ionization energy is similar to what other trend on the periodic table?
Definition
 electron affinity
Term
Definition
 measure of the size of an atom; it increases down a group, but decreases across a period
Term
 Why does atomic radius decrease across a period?
Definition
 because as electrons and protons are added, the attraction between the nucleus and electrons increases, making the atom more "condensed"
Term
 When an atom gains electrons, it
Definition
 gets larger becomes an ion has a negative charge
Term
 Metals typically form ___ ions and are found on the ___ of the periodic table.  Non-metals typically form ___ ions and are found on the ___ of the periodic table.
Definition
 positive, left negative, right
Term
 What is the difference between ionization energy and electron affinity?
Definition
 ionization energy= energy required to "pluck" an electron from the atom electron affinity= energy given off when an electron is gained
Term
 Which "block" contains the alkali metals and alkaline earth metals?
Definition
 s-block
Term
 Which "block" contains the non-metals?
Definition
 p-block
Term
 Which "block" contains the transition metals?
Definition
 d-block
Term
 What makes transition metals unique?
Definition
 They are: good conductors of heat/electricity shiny, malleable, ductile
Term
 What makes alkali metals and alkaline earth metals unique?
Definition
 they are highly reactive, soft metals
Term
 What makes the halogens unique?
Definition
 they are highly reactive non-metals
Term
 Air is a mixture of gases including oxygen, nitrogen, helium, hydrogen and traces of other gases.  Which gas makes up most (70+%) of earth's air?
Definition
 nitrogen
Term
 Which "block" on the periodic table is the only one that contains both metals and non-metals?
Definition
 p-block
Term
 What is the formula for the following: sulfate sulfide ammonia ammonium
Definition
 SO4-2 S-2 NH3 NH4+1
Term
 When atoms lose or gain electrons, they are trying to form stable electron configurations similar to which family?
Definition
 noble gases
Term
 Name the compound: NaNO3 SBr3 CaF2 KCl * 5H2O
Definition
 sodium nitrate sulfur tribromide calcium fluoride potassium chloride pentahydrate
Term
 When is the prefix "mono" used in naming compounds?
Definition
 only on the second word of a covalent compound, never on the first.
Term
 What does the Roman numeral next to a transition metal tell you? ex. copper (II) sulfate
Definition
 it tells you the ion charge (positive) on the transition metal
Term
 What does an acid have in its formula? What does a base have in its formula?
Definition
 H+ ion OH- ion
Term
 Which is the stronger covalent bond, a single bond or double bond or triple bond?
Definition
 triple is strongest, then double, then single
Term
 Which covalent bonds are the longest, single, double or triple bonds?
Definition
 single bonds are longest, then double, then triple
Term
 How many single covalent bonds can one carbon atom have?
Definition
 4
Term
 alkane
Definition
 single chain hydrocarbon with the formula CnH*2n +2 ex. C8H18
Term
 What does "Max eats peanut butter" refer to?
Definition
 naming alkanes and alcohols Max = methane/methanol eats = ethane/ethanol peanut = propane/propanol butter = butane/butanol
Term
 allotrope
Definition
 a pure substance with different structural forms
Term
 What are the three most common allotropes of carbon?
Definition
 graphite diamond buckminster fullerine (buckyball)
Term
 alcohol
Definition
 a hydrocarbon in which a hydroxide (OH) has replaced CH3 on one side of an alkane ex. ethane = CH3CH2CH3 ethanol = CH3CH2OH
Term
 What are alcohols most used for?
Definition
 they are burned for fuel
Term
 alloy
Definition
 a mixture containing metals produced by melting them together
Term
 Which of the following is NOT an alloy? steel bronze silver brass
Definition
 silver, it is an element
Term
 molarity
Definition
 moles per liter mol/L
Term
 molality
Definition
 moles per kilogram mol/kg
Term
 What formula do we use to calculate Molarity?
Definition
 Molarity = # mols / molar mass
Term
 In words, what is molarity?
Definition
 concentration of a substance in a liquid (usually water)
Term
 How do we figure out the number of mols of a substance?
Definition
 # mols = grams of substance / molar mass
Term
 How do we figure out molar mass?
Definition
 1. Look up each element's mass 2. Multiply by the # of atoms of that element 3.  Add all the numbers together
Term
Definition
 6.02 X 10^23 or 1 mole
Term
 How do we calculate the number of particles of a substance?
Definition
 # particles = (# mols ) X (6.02 X 10^23)
Term
 What type of reaction is shown below?   2HgO --->  2Hg + O2
Definition
 decomposition reaction
Term
 What type of reaction is shown below?   2Mg + O2 --->  2MgO
Definition
 combination reaction OR synthesis reaction
Term
 What type of reaction is shown below:   2K + 2H2O --->  2KOH + H2
Definition
 single replacement reaction
Term
 What type of reaction is shown below:   Br2 + 2NaI --->  2NaBr + I2
Definition
 single replacement reaction
Term
 What must be true for a metal to replace another metal (or hydrogen) in a single replacement reaction?
Definition
 it must be more reactive (from the activity series chart) than the one it replaces
Term
 What type of reaction is shown below:   Na2S + Cd(NO3)2 --->  CdS + 2NaNO3
Definition
 double replacement reaction
Term
 Balance this reaction:   NaCN + H2SO4 --->  HCN + Na2SO4
Definition
 2NaCN + H2SO4 --->  2HCN + Na2SO4
Term
 Balance this equation, give the type of reaction and name the compounds:   Ca(OH)2 + HCl --->  CaCl2 + H2O
Definition
 Ca(OH)2 + 2HCl --->  CaCl2 + 2H2O double replacement reaction calcium hydroxide + hydrogen chloride (hydrochloric acid)  ---> calcium chloride + dihydrogen monoxide (water)
Term
 What type of reaction is shown below,  and name the compounds:   2C8H18 + 25O2 --->  16CO2 + 18H2O
Definition
 combustion (burning) reaction   octane (gasoline) + diatomic oxygen (oxygen gas) --->  carbon dioxide + dihydrogen monoxide (water)
Term
 How many total electrons are involved in a double covalent bond?
Definition
 4
Term
 polarity
Definition
 describes if a molecule has a positive side and a negative side; like a magnet
Term
 How do we determine whether a molecule is polar or non-polar?
Definition
 check the electronegativity chart:  a difference greater than 0.4 means polar...if the molecule is diatomic, it must be non-polar
Term
 electronegativity
Definition
 a number given to elements to describe "how negative" or "how positive" they are
Term
 Determine if the following is polar or non-polar: Na2S O2 TeCl2 Electronegativities: Na=0.9  S=2.5  O=3.5  Te=2.1  Cl=3.0
Definition
 Na2S  --->  polar (EN:  2.5-0.9=1.6) O2 ---->  non-polar (diatomic) TeCl2 ----> polar (EN: 3.0-2.1=0.9)
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