Chemistry equations Flashcards
Formula used to find fingerprint of gaseous elements
f= frequency lambda=wavelength c= speed of light h= plank’s constant (6.63 x 10-34 J•s)
**Can only predict E of atoms or ions with one electron (Bohr atom)
Change in E predicts wavelength of photons emitted when electron fall to lower E level (emission) or jump to higher E level (absorption)
Name the type of radioactive decaythat can be stopped by skin or paper
Alpha Decay
Type of radioactive decay that emits 2 protons and 2 neutrons
Alpha Decay
21084PO ►20682PO
Alpha Decay
Too many neutrons, so neutron is converted to proton + electron
Beta Neg. decay
Atomic Number + 1
Beta Neg Decay
146C►147C
Beta Neg Decay
Too few neutrons, proton ocnverted to neutron and poistron
Beta Pos. Decay
Atomic # = -1
Beta Pos. Decay or Electron Capture
189C►188C
Beta Pos Decay
What is the difference b/w Electron Capture and Beta Pos. Decay?
both have too few neutrons, but electron capture captures electron from closest shell to convert proton into neutron. Beta pos. decay converts proton into neutron without capturing electron.
What type of radioactive decay needs concrete or Lead to stop?
Gamma Decay
Atomic # and mass stay the same in what radioactive decay?
Gamma
What does Gamma Decay emmit?
gamma photons
Nuclear Binding Energy
c=3x108m/s
1ev= 1.6x10-19J
1amu= 1.66x10-27kg
EBin ev for equation
m in amu
The greater the binding energy, the more ______ the nucleus
stable
Formal Charge Equation
FC=V-1/2B-L
FC= formal charge
V=#valence electrons
B=#bonding electrons
L=#lone-paired electrons
Amount of E required to complete transition ___
heat of transition (Delta H)
what is formula for calculating energy required to complete phase transition/change
q=nXΔH
q=heat
n= #of moles
H=change of phase change
q=nXΔH
q and H are +, heat is _____
absorbed
q=nXΔH
q and H are -, heat is _______________
released
To calculate temperature change in a reaction
q=mcΔT
q=heat added or released
m=mass of sample
c=specific heat of substance
What is specific heat?
How resistant a substance is to change in temperature. The greater the specific heat, the less there will be a change in temperature
Define calorie
Amount of heat required to raise 1 gram of water by 1degree C
1cal= ?J
4.2
1atm=?torr=?mmHg
(pressure)
760, 760
1cm3=?cc=?mL
(volume)
1cc, 1mL
1m3=?L
(volume)
1000
1atm=?kPa=?Pa
(P)
101.3kPa
1x105Pa
The ideal gas law
PV=nRT
R=universal gas constant (.0821L-atm/kmol)
T in kelvins
combined gas law
P1V1/T1=P2V2/T2
At constant P, how does V relate to T?
V1/T1=V2/T2
At constant T, how does P relate to V?
P1V1=P2V2
At constant V, how does P relate to T?
P1/T1=P2/T2
Boiling Point elevation equation?
ΔTb=kbim
kb= solven’s boilng point elevation constant
i is van’t hoff factor (basically how many ions are in it?)
m= molal concentration of the solution (molal=#mol/kg)
Freezing point depression equation?
ΔTf=kfim
van’t hoff equation? aka osmotic P
Π=MiRT
Π=osmotic P in atm
M-molarity
i=van’t hoff factor (how many ions?)
R=Planks constnat .0821 L•atm/k•mole
T = T in K
If keq < 1 →
If keq = 1 →
If keq > 1 →
rxn favor reactants
rxn balances reactants and products
rxn favors products
keq stands for, which is constant IF ___________
equilibrium constant, constant if T is constant
Q stands for ____
if Q < Keq ______
if Q > Keq _________
reaction quotient when rxn is not at equilibrium
Rxn proceeds forward
Rxn proceeds backwards
ksp stands for
solubility product constant - how easily a salt dissolves in water
In a problem with solubility constant (ksp) what is left out of equation?
solids
What does Ka stand for?
acid ionization - tells if products or reactants are favored.
The larger the Ka value the _____________ the acid
stronger (Ka>1 is a strong acid)
What does kw stand for?
autoionization of water aka the ion product constant of water
What is the kw of water at 25ºc?
1 x 10-14
What is the formula for PH in its relation to acids? Bases?
PH = -log [H+]
[H+]=10-PH
pOH=-log[OH-]
[OH-]=10-pOH
What is the neutralization formula?
a x [A] x VA= b x [B] x VB
a = # of acidic hydrogens per formula unit,
b = how many H+ ions the base can accept
VA is volume of acid, same for Vb, A is concentration of acid
Henderson-Hasselbach equation
pH=pka + log( [CB]/ [weak acid] )
First law of thermodynamics equation
ΔE=q+w
Change in E = heat + work
Gibb’s free energy equation
ΔG = ΔH - TΔS
H - enthalpy
S - entropy
What does ΔG tell you about chemical rxn?
Whether it’s spontaneous or not.
If…
ΔG < 0
ΔG = 0
ΔG > 0
spontaneous, forward directoin
equilibrium
nonspontaneous
What is the equation for Gibbs free Energy at equilibrium?
ΔGº = -RT lnKeq
What equation relates Gibbs free energy to redox rxns?
ΔGº = -nFEº
n = # of moles of E transferred
F is constant = 96500 coulombs
Eº = reduction potential
At STP 1 mole of an ideal gas occupies ?L
22.4L
