Chem Unit 3
combined gas law
(P1V1)/T1=(P2V2)/T2
serial dilution
A stepwise dilution of a substance in solution
formula for energy of light
E = hv Energy = Planck's constant x frequency
The diagram above represents four cations, all shown to the same scale. Which cation would be predicted by Coulomb's law to have the strongest ion-dipole attraction to water, and why?
Mg 2+ Coulomb's Law states that there is greater attractive force over a smaller distance. Since it has the largest large with the smallest size, it'll have the greatest Coulombic forces
tetraamine copper (II) sulfate
[Cu(NH3)4]SO4
pressure
molecule collisions
is something completely insoluble
no, everything dissolves a little
blue 1 dye
only colored substance in gatorade
OH- groups
polar
Which has the stronger intermolecular force, non polar or polar
polar
colors ranked from highest energy to lowest energy
purple --> red
paper chromatography
separates small quantities of a mixture into components dyes have different polarities that can be separated with paper chromatography
Distillation
separates substances based on their boiling points
use formula of best fit line of the calibration curve
so true
calculate mass of dye (liters to milligrams)
(1L x 1.56 uM x 1 mol x 793g x 1000mg)/(1L x 10^6umol x 1 mol x 1g)
mole fraction
(moles of solute)/(mole of total)
how to get absorbance from transmittance (T)
-log T
absolute 0
0 K
r
0.08206
Equimolar samples of CH4(g) and C2H6(g) are in identical containers at the same temperature. The C2H6(g) deviates much more from ideal behavior than the CH4(g) does. Which of the following best helps explain this deviation?
C2H6 is more polarizable the the non polar CH4
strong acids
HI HBr HCl HNO3 HClO3 HClO4 H2SO4
Kinetic Energy Formula
KE=1/2mv^2 v = velocity
Molarity formula
M=mol/L
Ideal Gas Law
PV = nRT
Boyles Law
PV=PV
The graph above shows how a particular real gas deviates from ideal behavior at very high pressures. Based on this information, which of the following is most likely the gas and gives the reason based on kinetic molecular theory?
SO2 because it has a greater volume. The graph depicted the curve to have a greater volume than the ideal gas curve. When pressure is high, the molecules with high volumes are more compressed, so they deviate from the ideal gas conditions because volume is not negligible
What happens when dye molecules absorb visible light?
Some electrons in the dye molecules move to higher energy levels
A solid compound of a group 1 (alkali) metal and a group 17 (halogen) element dissolves in water. The diagram above represents one type of solute particle present in the solution. Which of the following identifies the solute particle and best helps explain how the solute particle interacts with water molecules?
The larger ion is positive because group 1 is larger than halogens. The positive ions are attracted to the central thing
Lab purpose
Use spectrophotometers to determine the concentration of dye in a sports drink
When you combine two gases in the same container, how do you find pressure
add the two pressures
When temperature increases...
average speed of molecules increase
formula for speed of light
c=λv speed of light = wavelength x frequency
Which has a higher melting point, covalent or dispersion forces?
covalent networks have the highest melting points
Why are diamonds harder than graphite if they are both pure carbon
diamonds have four covalent bonds between carbon molecules. graphite is made up of layers that are attracted to each other by dispersion forces
what makes something a conductor
dissolved ions
UV visible
electronic transition moving electrons between orbitals
experimental molar volume
experimental L/experimental mol
speed of particles at a fixed temperature
gas particles have a distribution of speeds that is dependent on the temperature
Kinetic Molecular Theory
gas particles have negligible volume gas particles are equally sized and do not have attraction move randomly perfect elastic conditions with no energy loss
What is most effective separation with paper chromatography?
if the dye portions are far apart they have the highest difference in affinity. This difference in polarity allows for a better separation
What makes LDF's stronger
increase surface area polarizability
manometer
instrument to measure pressure
If a substance reflects a certain color, what does is absorb?
it absorbs the opposite color
rule for dissolving
like dissolves like
temperature
measure of average kinetic energy of particles in a sample of matter
microwave
molecular rotation the electrons rotate and create frictions against each other
Infrared
molecular vibration if you shine infrared light on a molecule, the electrons will vibrate
which have higher average speed, small or large molecules
small molecules (the gas with the higher average molecular speed has the lower molar mass)
soluble qualities
strong electrolytes
hydrogen bond
strong intermolecular force between hydrogen and a fluorine, oxygen, or nitrogen
vapor pressure
tendency of a liquid to become a gas proportional to temperature when a vapor pressure = atomic pressure
why are zinc ions colorless
the electrons have no other orbital sub shells to move to
solvent front
the furthest point reached by the solvent in chromatography paper
How to compare melting points
the one with stronger intermolecular forces have higher melting points because it requires more energy to separate the bonds
real gas differences from ideal gas
there are attractive forces due to the partial negatives and positives
What makes salts dissolve?
there are strong ion-dipole forces between K+ and the H2O atoms as well as Cl- and the H2O atoms. This causes the ions to dissociate in the solution
suspension
water + oil
standard molar volume of gas lab
water levels must be equal 22.4L standard molar a gas, 0C, 1 atm
Beer's Law's relation to the absorbance and concentration graph
x is concentration y is absorbance m is the molar absorptivity and path length b is 0 of distilled H2O
