General Chemistry Flashcards
what is the definition of % mass solution??
Mass solute/ ( mass solute + mass solvent = mass solution )
3 fold dilution
- dilute to 3x less than initial
- 2 part water and 1 part solution
Oxidation
it loses electrons
mneumonic “ OIL RIG”
OIL - oxides it loses e-
RIG = Reduction it gains e-
reduction
gains electrons
Reducing agent
helps reduce other agents ( REDUCTANT) and it get oxidized
oxidizing agent
acts like an oxidant ( oxidizes other reagents) and gets itself redued.
Solubility Rules: Salts containing Alkali metals cation with ( Li+, Na+, K+, Cl-)
water soluble
Solubility Rules: Salts containing Nitrate( NO3-)
water soluble
Salts containing halide anion( Cl-, Br-, I-)
water soluble except Ag+, Pb2+
Solubility Rules: Salts containing (SO4) 2-
sulfate
water soluble except Ba2+, Pb 2+, Hg 2+, Ca2+
Solubility Rules: Salts containing ( OH-) hydroxide
are slightly water soluble.
- KOH and NaOH are substantially soluble, while Ca(OH)2, Sr(OH)2, and Ba(OH)2 are fairly soluble
Solubility Rules: Salts containing Carbonate( CO3) 2-, chromate ( CrO4-), phosphate anion ( PO4) 3-, sulfide ( S2-)
Slightly soluble
MNEUMONIC FOR LIMITING REAGENT
mole ratio A/B > balanced mole ratio A/B
then what is the limiting reagent?
mole ratio A/B
mole ration A/B > balanced mole ration A/B
THEN B is the limiting reagent
mole ratio A/B
oxidation state of oxygen
-2 except with peroxide
oxidation state of hydrogen
+1
oxidation state of halide
-1
1/5=
0.2
1/6=
0.166
1/7=
0.143
1/8=
0.125
1/9=
0.111
1/10=
0.1
1/11=
0.091
1/12=
0.083
for molecular molecules, the number of hydrogens must be
it must be an even number
Does molality change with temperature?
NO , molality doesn’t change with temperature
Does molarity change with temperature
Yes, molarity changes with temperature
Does density change with temperature
Yes, density changes with temperature
Does specific gravity change with temperature
Yes, specific gravity changes with temperature
Lower pKa ->
stronger acid and weaker base
Higher pKa
weaker acid and stronger base
if pH >pka, the molecule is?
deprotonated
if pH
protonated
Solid >—solid/liq—-> Liquid—> lig/gas—> gas
is what kind of process
endothermic ( it absorbs energy to break the bonds and release the molecules)
mneumonic - it takes energy to break bonds
Solid
exothermic ( release energy as bonds are made)
Mneumonic - when bonds are made, everyone is happy and energy is released.
Name the types of systems in thermodynamics
- isolated
- closed
- open
Define Isolated system
no exchange of hear, work, or matter with surroundings
Define closed system
exchange of heat and work, but no matter with the surrounding
Define open system
exchange of heat, mass, and work with the surroundings
Define a state function
a system that is path -independent and depneds only on the initial and final states
examples: delta H ( enthalpy) Delta S ( entropy) Delta G ( Gibbs free energy) delta U ( internal energy change)
Conservation of Energy
- the total amount of energy in an isolated system remains constant.
total energy is neither gained nor lost, it is merely transferred between the system and its surrounding
.
define Endothermic reactions
Energy is ABSORBED by the reaction in the form of heat.
delta H is positive
MNEUMONIC : H STANDS FOR HEAT
Define exothermic reactions -
energy is RELEASED by the reaction in the form of heat
Delta H is negative
MNEUMONIC : H STANDS FOR HEAT
delta H is the change in heat content of a reaction
+ means heat is ABSORBED
- means heat is RELEASED
Bond dissociation energy define
it is the energy nrequired to break bonds
Energy in the reactants - products
the sign is POSITIVE because energy is required to break bonds
define Entropy
a measure of disorder
measured in J/K
Entropy of gas>liqiud>solid
define free energy
Free energy is the energy available that can be converted to do work.
Delta G = Delta H - T delta S
T is in kelvin
Sponantenity of a reaction relies on what?
Gibbs free energy
Spontaneous reaction has what sign of delta G
NEGATIVE aka exogonic
NONSPONTANEOUS reaction has what sign of delta G
POSITIVE aka endogonic
NONSPONTANEOUS reaction has what sign of delta G
POSITIVE aka endogonic
First law of thermodynamics
Del U= Q+W
is based on the principle of conservation of energy, and it basiclaly says that the change in total internal energy of a system is equal to the contributions from work and heat.
what is the Q in the first law of thermo?
HEAT
Q is positive –> the heat is being absorbed
Q is negative –> the heat is being released
What is the W in the first law of thermo?
WORK
Work is positive - when work is being done ON the system
Work is negative - when work is being done BY the system.
Second law of thermodynamics Entropy
- 2nd law states that the things like to be in a state of hihger entropy and disorder
- an islolated system will increase in entropy over time
- an open system can decrease in entropy, but only at the expense of a greater increase in entropy of its surroundings
The universe as a whiole is increasing in entropy.
delt S >= q/t
reversible systems Delt S=q/t
irreversible systems det D>q/T
define heat of fusion
del H fusion = energy input needed to melt something from solid to liquid and vice versa
latent heats are measured as Joules/mass
therefore Q=mL where m = mole and L= latent heat of vaoprization or fusion
define heat of vaporiation - delt H vap =
= del H vap= energy input needed to vaporize something from liquid to gas and vice versa.
latent heats are measured as Joules/mass
therefore Q=mL where m = mole and L= latent heat of vaoprization or fusion
Area of a PV diagram gives you what?
WORK!
PV diagrams depict thermodynamic processes by plotting pressure againsst volume
Name the types of processes in thermodynamics
- adibatic process
- isothermal processs
- isobaric process
- isovolumetric ( isochoric ) process
Define Adiabatic process
- NO heat exchange
Q=0
Det U = W
Isothermal Process
no change in temperature aka delta U = 0
the change in work = change in heat
isobaric process
constant pressure
W=Pdet V
P=0
Isovolumetric process ( isochoric(
no change in volume.
work = P det V=0 because there is no change in volume.
det U = Q