CHEM MIDTERM TOPIC BLAHDOM
Terms
undefined, object
copy deck
- potential energy and stability
- more potential energy=less stability
- how do you find the heat of reaction?
- Products potential energy-reactants potential energy
- heat of reaction pos. and neg. values
-
exo=pos. value
endo=neg. value - which are endothermic reactions
- SLG
- which are exothermic reactions
- GLS
- energy of activation
- energ needed to start a reaction
- whose energy of activation is higher, endo or exo?
- exo
- what are substances
- elements and compounds
- which way does heat travel
- from higher to lower temp.
- transducer
- something that converts one form of energy to another form of energy
- what increases as time increases in a heating/cooling curve
- potential energy
- when is the first time you see something in its new phase?
- only at the point when it reaches its highest temp.
- what is specific heat
- 4.18 J/g C
- what is the formula for heat
-
Q=M delta T C
heat=mass x change in temp x specific heat - what happens to heat in a heating curve
- it is absorbed
- what happens to heatin a cooling curve
- heat is released
- what kind of reaction does a coolking curve show
- exothermic
- what kind of reaction does a heating curve show
- endothermic
- what processes are in a heating curve
-
1. melting (fusion)
2. boiling (vaporization) - what processes are in a coolking curve
-
1. freezing (solidification/crystallization)
2.. condensation - wavelengths and energy
- the shorter the wavelength, the greater the energy
- what happens when electrons fall back down from their excited state to their ground state
- they give off energy
- what does a lower energy level mean about stability
- it is more stable
- atom
- smalllest part of an element that retains the properties of that element
- stability vs. # of neutrons in an isotope
- more neutrons=less stable
- quantum
- packet of energy required to boost an electron to a higher energy level
- order of penetrating power of decay thingys
-
most powerful=gamma
2nd=beta
3rd=alpha - what do all radioactive things end up as?
- stable, radioactive lead
- half-life
- the amount of time for half of a substance to decay
- what do you do to go forward in time with half life
- divide by two
- what do you do to go backwards in time with half life
- multiply by 2
- what is more stable hydrogen and oxygen separate or together?
- together- more stable, less pe
- fusion
- A+B---AB + energy
- binding energy
- the amount of energy released when a nucleus is formed fro its component parts
- fission
- chain reaction breaking up
- characteristics of ionic compounds
-
1. high melting and boiling pts
2. solid at room temp
3. crystalline
4. do not conduct electricity in teh solid state - characteristics of molecules
- low melting pt, low boiling pt, generally are gases
- metal and nonmetals losing and gaining electrons
-
metals lose electrons
nonmetals gain electrons - ionic bonds and electronegativity
- if the electronegativity is greater than 1.7
- covalent bonds and electrongegavity
- electronegaivity diffference is less than 1.7
- nonmetlas and metals and electronegavitiy
-
nonmetals have high electronegavitity
metals have low electronegaivity - cations and anions
-
cations=metals in lew dot
anions=nonmetals in lew dot - where is the most electronegative part of the periodic table
- upper right
- wehre is theleast electronegative part of the periodic table
- lower left
- why is there no way to measure the electronegativity of noble gases?
- bc they dont react w/ any other atoms
- what is the only kind of attraction a molecule can have if its balanced?
- van der waals
- molecule size vs. forces
- bigger molecule=bigger forces
- distance between molecule vs. forces
- the closer the molecules, the great the forces
- what kind of attraction is there between non-polar molecules
- weak
- how do you find out what compound has the highest boiling pt.
- the one with the most attraction between them
- sea of mobile electrons
-
-in metals
electricity flows through them bc electrons are mobile; they flow and are alwyas moving so they give up electrons easily - what kind of bonding do all carbon and hydrogen compounds have
- covalent
- how do you know if something dissolves
- like dissolves in like
- why do metals have a low melting pt
- sea of mobile electrons
- polarity and difference in electronegativity
-
most polar=greatest difference in electronegaivity
least polar= least difference in electronegativity - what has a triple covlanet bond
- N2
- bonding breaking and forming and energy
-
bond breaking absorbs energy
bond forming releases energy - degenerate
- alll of the same energy level
- van der waals
- the weak intermolecular attractios between nonpolar molecules
- htdrogen vonding
- bonding between hydrogen and oxyge, hydrogen and flourine, and hydrogen and nitrogen
- molecular-ionic attraction
- ionic charges cause attraction
- dipole-dipole attraction
- polar attractions between two molecules
- how to name binary acids
-
hydro+_____ic acid
AB - how to name ternary acids
-
H+ polyatomic ion
i ate something icky
ate-->ic
mighty mouse
ite-->ous - three ways to test for carvon dioxide
-
1. extinguishes flame
2. limewater goes from clear to cloud
3. bromythymol blue turns yellow - what is avogardros #
- 6.02 x 10^23
- what do all acids contain
- hydrogen