Exam 1 Flashcards
Enthalpy
Delta H
Heat absorbed or emitted during a reaction under constant pressure
Entropy
Number of arrangements
Tells you which way heat transfers
Electronegativity
- Increase across
- Decrease down
- An atoms tendency to form bonds
Ionization energy
-increase across
-decrease down
-energy required to remove an electron
Reason: valence shell stability, electron shielding
Effective nuclear charge
- charge felt by valence electrons after calculating electron
- protons minus core electrons
- determines all periodic trends
Solution
- Homogeneous mixture of 2 or more components
- can’t unmix
Mixture
- heterogeneous
- diff composition
- easy to unmix
What factors affect solubility?
- nature of solvent
- nature of solute
- entropy change
- temperature
- Gibbs free energy
immiscible
the solute and solvent do not mix up
thermal energy
- sum of kinetic and potential energy
- relies on energy and composition
solvation shell
H2O molecules are locked in place around molecule
clathrates
water forms a cage structure around molecules
high pressure and low temp
surfactant
polar and non polar parts
used to break up oil
substitute alloy
if the atoms are of similar size, the solute atoms substitute for the solvent atoms
interstitial alloy
if the solute is smaller the atoms sit in the holes
Coulomb’s law
Unlike charges attract
-explains interactions between and within atoms
F=k(q1•q2)/r^2
-q is force
First law of thermodynamics
Energy can neither be created nor destroyed
State function
Depends only on initial and final states
Entropy
- measure of possible arrangements
- tells you which way heat will transfer
Enthalpy
Heat absorbed or emitted in a reaction under constant pressure
-exothermic and endothermic
The second law of thermodynamics
-for any change the total entropy of he universe must increase
Combustion reaction
Releases energy
Saturated
No more solute will dissolve
Units
Percent mass- 10% solution has .1 g diluted per 1 g solution
Ppm- 1 microgram per gram (mg/L)
Ppb- 1 nanogram per gram (ug/L)
Hydrophilic and hydrophobic
Hydrophilic likes water
Micelles
Organized clusters of amphipathic molecules
Nonpolar substance creates inverted
Lipid bilayer
Hydrophobic on inside hydrophilic on outside
Alloys
Mixtures of metals
Substitute alloy: atoms of similar size, solute atoms substitute for solvent
Interstitial: solute is smaller, atoms sit in the holes
