Qualitativeobservations not involving a measurement; examples include elemental symbol, color, malleability, ductility, and conductivityQuantitativemeasurements resulting in a number; examples include molecular mass, density, melting point, and boiling pointName the steps in order for chemical analysis1. Formulate the question
2. Select an analytical procedure
3. Obtain a sample
4. Prepare the sample
5. Sample analysis
6. Report results
7. Draw conclusionsSI Units: Lengthmeter (m)SI Units: Masskilogram (kg)SI Units: Timeseconds (s)SI Units: Electric currentampere (A)SI Units: TemperatureKelvin (K)
Equation Conversions:
TF = (9/5)C + 32C
๐K=๐C+273.15TK=TC+273.15
Ex:
๐K=(โ268.93 โC)+273.15=4.22 KSI Units: Luminous Intensitycandela (cd)SI units: amount of substancemoles (mol)SI Units: Plane angleradian (radius)SI Units: Solid anglesteradian (sr)10^-12pico (p)10^-9nano (n)10^-6micro (ยต)10^-3milli (m)10^-2centi (c)10^-1deci (d)10^1deca (da)10^2hecto (h)10^3kilo (k)10^6mega (M)10^9giga (G)10^12tera (T)molaritymoles of solute per liter of solutionmolalitymoles of solute per kilogram of solventdensitymass of substance per unit volumeweight percentmass of a solute per mass of the total solution, multiplied by 100%volume percentvolume of a solute per volume of the total solution, multiplied by 100%parts per millionmicrograms of analyte per gram (or millimeter) of sample (X10^6)parts per billionnanograms of analyte per gram (or milliliter) of sample (X10^9)formal concentrationthe total concentration (expressed in units of molarity) of all species in a given substanceHow is the number of moles related to the number of particlesNumber of moles is directly proportional to the number of particlesSolution Preparation Steps1. Transfered the measured amount of NaCl to the volumetric flask
2. Dissolve the NaCl in less than 250 mL of water and mix well
3. Add more water to the flask, but still under a total volume of 250.0 mL and mix
4. Dilute the solution with water to the 250.0 mL mark
5. Hold the cap firmly in place and invert the flask many timesWhat is the buret rinsed with and why?The titrant should be used to ensure that when added to the buret it will not be diluted with waterA volumetric flask is calibrated to hold a liquid at what temperature?20 CTDto deliver, buretTCto contain, volumetric flaskVolumetric Glasswarevolumetric flasks, pipets, and buret
more resistant to strong acids and bases
smaller change in size and volume with temperature change
more accurate volume measurementsRoutine glasswarelower price
used for storing and handling solutionsVolumetric pipettransferring 5.00 mL of solution from one container to anotherBuretdelivering different volumes of 0.200 M HCl solution for titration of a baseMohr pipetdispensing 6.6 mL of a solution to a series of test tubesmicropipettransferring 50 ยตL of an enzyme solution to a test tubegraduated cylinderadding 45 mL of concentrated HCl to a beaker of waterBuoyancy CorrectionMultiply mass of water by buoyancy correction factor (found in table, corresponds with temperature)Exact numbersthere is no uncertainty
Ex:
2.54 cm = 1 inch
1 cm^3 = 1 mL
12 objects = 1 dozen
1000 mg = 1 gram
metric prefixes define how many of a unit are equivalent to one base unitMeasured Numbershas uncertainty in the value
quantified using a tool like a tape measure, ruler, or balance
the precision of the measuring tool determines the amount of uncertainty in the measured valuePrecision(standard deviation/mean) X 100Accuracy((Experimental mean value - known value)/known value) X100Systematic ErrorIncorrect instrument calibration, contaminated reagents, or other experimental errors
cause the average of many trials to be skewed in one direction from true valueRandom Errorsmall variances in instrumentation and glassware measurements, present regardless of care taken by experimenter; unavoidablePrecisionseveral measurements are close to each otherAccuracyindividual measurements are close to an accepted value
