Experimentation Flashcards
Cracked glassware
Treat as if it were broken
Disposal of broken glass
Sweep it up,
Place in the appropriately marked bin
Record Identity of item on the lab list,
Get a replacement
Drawer isolation
Glassware is kept away from all other lab materials
Fume hoods
Hood over the top of the experiment to suck away vapors
Sink disposal
Water only,
No chemicals, tissues, matches
Nesting
Arrangement of beakers so that the dmaller beakers fit inside the larger beakers
Spillage clean up
Wipe away with a wet sponge
Distilled (RO) water
Pure water used for chemical reactions
Cleaning glassware
Use dish detergent, not soap
Use sponge not scrub pad
Allow to air dry, inverted
Drying agents
Used to quickly dry glassware
ie acetone
Measuring pipet
Glass tube with a rubber bulb used to suck liquids of a specified volume
Forceps
Special tweezers used to pick up a solid object
Watch glass
Used to cover reactions in glass containers
Weighed to measure residue mass
Acts as a great cutting surface
Evaporating dish
Porcelin half-sphere, used to hold a substance of small volume during heating
Mortar and pestle
Bowl and rounded stick used for crushing a solid into powder
Volumistic flask and ground-glass stopper
Tear-shaped glass container with glass cap to contain all of the mass of the reaction inside
Round bottom flask
Best used to maximize heat dispersion for the material inside, for bringing a substance to a boil
Vaccum flask
Flask with additional nozel to hook up to a suction device to create a pressure difference for filtration
Erlenmeyer flask
Glass in which volume can easily be measured
Test tube
Glass container used for adding one substance to another for observation
Beaker
Ideal container for heating and later pouring,
Glass cylynder
Well spot plate
Plastic square with smaller holes used for comparing a substances reaction to a variety of materials
Stirring rod
Maximizes molecular interaction within a reaction
Beaker tongs
Instrument used to move a heated beaker
Test tube holder
Accesory to a ring stand, complete with a clamp to hold the test tube over a bunsun burner or ice bath
Thermometer clamp
Used to hold a thermometer over a reaction
Test tube holder
Metal inverted tweezers used to lift a test-tube
Utility clap
Used to hold a glass container from a ring stand
Scoopula
Used for transferring powderized solids
Beryl pipet
Used to transfer small volumes of liquid
Ring
Used to hold a metal plate over a bunsun burner from a ring stand
Wire triangle
Used to hold a bowl in the ring from the ring stand
Crucible tongs
Used to lift small heated bowls
Graduated cylinder
Used to measure and pour liquids of a specific volume
Gravity funnel
Used to control the dispersion rate when pouring a liquid
Buechner funnel
Used to filter substances
Funnel holder
Used to hold a funnel from a ringstand
Heating angle
45 degrees to the side
Test tube heating
Test tube holder to position test tube with top of the liquid over flame 45 degrees to the side, facing away from yourself, towards fume hood
Buret
Measures liquid dispersed into container, reads bottom to top
Buret holder
Mechanical clamp that holds buret from the ringstand
Eye protection occurances
ALWAYS
Glasses in the lab
Still need safety goggles
In case of fire
Go get prof
DO NOT DEAL WITH IT YOURSELF
Marked with Red
Flamable
Marked with yellow
Both flammable and explosive
Marked with blue
Biohazard
Occurance of chemical burns
Flood area with cold water
Lab clothing
Closed toes,
Covered from neck to knees, tight clothing
Hair tied back
Food in the lab
Never allowed
Smelling
Hold container away, waft fumes towards you
Weighing objects
Wait until cooled
Weigh container first, subtract from the total
Significant figures
Record the lowest number of significant figures given from the rest of the data
Clamping test tubes
Clamp the tube at the top
Above the surface if the liquid
Tasting
NEVER taste
Mixing within tubes
Spank the tube
‘Spanking’
Hold tube at the top,
Flick repeatedly at the bottom
Decant liquids
Touch glass rod to beaker spout
Pour down the rod and into container
Proper flame
Blue non-luminous flame
Water bath
Test tube with substance is dipped in water as the water is being heated
Gravity filtration
Set gravity funnel over beaker with filter paper inside
Decant liquid into it
Boiling chips
Stones that allow water to reach its boiling point faster
Heating a flamable liquid
Place liquid in crucible with lid
The bunsun burner setup
1) Attach burner tubing to the gas
2) set gas control to half-open
3) adjust gas contol on the burner to half open too
4) light the flame
5) turn the burner off when not in use
Percent error
(MeasuredValue-acceptedValue)/(acceptedValue)
Rounding,
5 round up
Extensive properties
Depend on the quantity of mass
Intensive properties
Properties do not depend on the quantity of material present
Dimensions
Length Width Height Radius Liquid depth
Caliper
Used for reading, incredibly small distances
Reading a meniscus
Use the lowest point
Liquid has a tendency to ‘climb’ the sides
Converting Farenheight to Celcius
C=(F-32)*(5/9)
Converting celcius to kelvin
K=C+273
Separatory Funnel
Cone shaped funnel set up in a ring stand, used to partition a mixture into two immiscible solutions of different densities
Distillation set up
Round bottom flask over a flame, with a distillation head attatchment. A thermometer loads into the top while a tube, connected by a ‘keck clamp’ runs out to ‘condenser’, that supplies water against the flow of gravity. At the other end, also connected by a keck clamp, is a dripping addapter, set over a beaker
Sources of chemical information
1) Material safety data sheet,
Contains LD50, lethal doses of chemicals
2) merck index
3) CRC handbook of chemistry and physics
Volumetric Pipet
Glass tube, wider in the middle and narrower at the top, used to move liquids at high volume
Comes with an attachment, on which the knob is cranked to draw the liquid up.
Finger is put down on the top, use pressure to deliver
Touch tip to the wall of the flask
Coffee cup Calorimeter
Filled with water at a certain temperature, material heated to a certain temperature is dropped inside.
Test with thermometer, until the temperature stops changing
Bomb calorimeter
Material is placed in container with pure oxygen.
Container contents are detonated while the container is submerged.
A thermometer is used to measure the change in temperature
Heat transferred equation
Q=cmΔT
C= specific heat of substance
Calculating specific heat
c=Q/(m*ΔT)
Q- heat transfered
Scientific method
Observe Hypothesis Experiment Record results Draw Conclusion
Titration set up
Functioning burret is positioned over a beaker
Positioned inside this beaker is a ph meter electrode
Ph meter electrode
Measures the concetration of the solution by the acid content
Simple beam spectrophotometer
A light source gives off wavelengths of visible light, in front of a ‘wavelength selector’ which splits the source beam into its component wavelengths and focuses them onto the sample (contained within a cuvette) the wavelengths pass through this to a ‘wavelength detector’ to measure the intensity, and convert it into an electrical signal, which is then passed to a a signal processor with a readout
Percent transmittence
(TransmittanceOfTheSample)/(transmittance of blank-sample) x100%
Absorbance from percent transmittance
A=-log(%T/100)
Extinction coeffient (ε)
Physical property of the sample. Depends on the wavelengths absorbed by the sample
Beer-lambert law
A= εbC
A- absorbance at a given wavelength
ε- extinction coeffient
b- the path of length
C- conentration in molarity
Calibration curve
Chart used to determine the conentration of unknown substances
Chalk for the ‘Spec 20’ Spectrophotometer
Worn down to a 45 degree angle,
And placed in the cuvette
Submerged beneath the substance
Used to reflect light though out the substance
Instructions for handling the curvette
Hold at the top, wipe to remove finger prints,
Slowly insert into the spectrometer
Settings for the ‘Ocean Optics USB2000’
1) click ‘OOIChem’
2) pull down the menu for Spectrometer
3) check ‘enable strobe’
4) set “Mode of Opperation” to ‘scope’
5) set the transmittence knob to 100% T
6) click ‘Reference’ and adjust integration time to the maximum setting
7) click ‘store’
What exactly happens to the Curvette
Light travels through the bottom half of the curvette (only nesisary to fill it half-way). Do not fill all the way (risk damage to the spectrometer)
Based on the orientation with which it is inserted, light can pass through the solution at either 5 mm or 10mm
When finished storing data from the spectrometer
Always Set to 0% Transmittance
Turn off from the switch
Remove the curvet from the holder
Stirring box and rod
Magnetic box used to stir with a rod inside the solution
Set up for a voltalic cell
Two beakers are placed side by side, each filled with a reacting solution, a KNO3 salt bridge is dipped from one beaker to another. In each beaker is a reacting electrode. Each of these electrodes is connected to one side of voltmeter
Set up for measureing volages of a half cell
A beaker filled with a Cu(NO3)2 solution. With a Cu strip connected to an voltimeter. The other end is attatched to an Fe strip in a FeSO4 solution in a porous cup, dipped in the Cu(NO3)2 solution from the same solution
Chromotagraphy
A variety of methods by which a mixture is sepperated
Ascending paper chromatogram
An amino acid dot that ‘climbs’ the paper, leaving behind its constituent components as the paper absorbs another substance
Set up Radial Chromatogram
Dots are set up in a circle around the center of a circular paper
Placed over a dish of NaCl solution with a paper wick running from through the center
Accuracy
Getting the result you want
Precision
The consistancy with which you get your results
Arithmetic mean
The average measurement
Average deviation from the mean for a specific measurement
(Measured value-mean value)/(mean value)
Standard deviation
[Sum of ((measurement-next measurement)^2)/(Number of meaurements-1)]^(1/2)
Least significant figures
Always written as ±StandardDeviation
Relative standard deviation
(StandardDeviation)/(mean) x100%
Doubtful digit
The last number in the final value when rounding to the lowest number of significant figures
Deviations from mean
The difference between each measurement from the average value
Goniometer
An instrument that not only measures an angle but allows the object to be rotated
Diffraction
The tendency for electromagnetic wavelengths to bend around an object
Dueterium
Hydrogen with two neutrons
Aka: heavy hydrogen
Disccantation
The process by which one substance is dried by absorbing the moisture into another substance
Supercritical drying
Transitioning a material from a liquid to a gas by raising the temperature and pressure beyond the supercritical point, and then lowing the pressure until the substance become a gas
Freeze drying
Lowering the temperature on a liquid, until it becomes solid, then lowering the pressure until it sublimates into a gas
Scanning electron microscope
Scans an object with a focused beam of electrons and produces an image based on the angular feedback
