Chem Lab Terms
Help!
|
|
||||
|---|---|---|---|---|---|
| Chelate | a compound containing a ligand (typically organic) bonded to a central metal atom at two or more points.
🗑
|
||||
| complexometric titration | is a form of volumetric analysis in which the formation of a colored complex is used to indicate the end point of a titration.
🗑
|
||||
| direct titration | a way to determine the contents of a substance quantitatively.
🗑
|
||||
| displacement titration | Here the analyte is treated with an excess of a second metal bound to EDTA. The analyte ion displaces the second metal from the EDTA complex
🗑
|
||||
| Lewis acid | electron pair acceptors
🗑
|
||||
| Lewis base | electron pair donors
🗑
|
||||
| Ligand | an atom or group of atoms bound to whatever atom you are interested in
🗑
|
||||
| monodentate ligand | ligand that bonds to a metal ion through only one atom
🗑
|
||||
| multidentate ligand | binds to the metal ligand through more than one ligand atom
🗑
|
||||
| Aliquot | portion that represents a whole
🗑
|
||||
| aliquot factor | portion of total solution
🗑
|
||||
| analyte | substance that is undergoing analysis (substance being measured)
🗑
|
||||
| analytical concentration | concentration when you weigh something and dissolve it→ the total number of moles in
🗑
|
||||
| equilibrium concentration | the actual concentration
🗑
|
||||
| density | m/v
🗑
|
||||
| molarity | moles solute/ L solution
🗑
|
||||
| molecular weight | molar mass ( mass of a molecule) calculated as the sum of the mass of each constituent atom multiplied by the number of atoms of that element in the molecular formula
🗑
|
||||
| weight percent | weight solute/ mL sample
🗑
|
||||
| qualitative analysis | identifying what is in an unknown
🗑
|
||||
| quantitative analysis | identifying how much is present
🗑
|
||||
| gravimetric analysis | mass of product is measured to determine how much unknown was present
🗑
|
||||
| analytical balance | measure to 4 decimal places
🗑
|
||||
| buret | used to titrate→ goes to 4 s.f. measures in mL
🗑
|
||||
| desiccant | drying agent in dessicator
🗑
|
||||
| desiccator | closed chamber containing drying agent—to keep samples dried
🗑
|
||||
| direct weighing | place directly on balance
🗑
|
||||
| hygroscopic | absorbs/ attracts moisture from air
🗑
|
||||
| indirect weighing | weigh by difference—do not weigh onto balance
🗑
|
||||
| meniscus | curvature of liquid caused by surface tension
🗑
|
||||
| pipet | used to transfer known amount of liquid- can go to 4 s.f.
🗑
|
||||
| tare | 0 a balance
🗑
|
||||
| top-loading balance | measures to 2 decimal places
🗑
|
||||
| volumetric flask | calibrated to contain certain vol of liquid at 20 degrees celcius when bottom of meniscus in in the right spot
🗑
|
||||
| parallax error | error that occurs when your eye is not at the same height as the meniscus
🗑
|
||||
| accuracy | difference between delivered and desired volume
🗑
|
||||
| determinate error | repeatable if measurement made same way (correctable)
🗑
|
||||
| indeterminate error | (random error)- from experiment
🗑
|
||||
| precision | reproducibility of replicate deliveries
🗑
|
||||
| degrees of freedom | where n is number of data points
🗑
|
||||
| confidence interval | range of values in which there is a specified probability of finding the true mean
🗑
|
||||
| Gaussian distribution | characterized by a mean and standard deviation—mean is center of distribution and standard deviation is width→ (bell shaped curve)
🗑
|
||||
| student’s t test | statistical tool used to express confidence intervals and to compare results from different experiments
🗑
|
||||
| Absorbance→ | most useful quantitity for chemical analysis (A)—higher the absorbance
🗑
|
||||
| absorbance spectrum → | graph showing how A (or epsilon) varies with wavelength
Beer's law→
🗑
|
||||
| calibration curve→ | absorbance at one wavelength is plotted against different concentrations in a series of standards
🗑
|
||||
| cuvet→ | cell which has flate
🗑
|
||||
| molar absorptivity→ | symbolized by epsilon
🗑
|
||||
| spectrophotometry→ | the use of electromagnetic radiation to measure chemical concentrations
🗑
|
||||
| transmittance → | the fraction of incident light that passes through a sample T=(P/Po)
🗑
|
||||
| wavelength→→ | crest- to- crest distance between waves
🗑
|
||||
| Aliquot | portion that represents a whole
🗑
|
||||
| aliquot factor | portion of total solution
🗑
|
||||
| analyte | substance that is undergoing analysis (substance being measured)
🗑
|
||||
| analytical concentration | concentration when you weigh something and dissolve it
🗑
|
||||
| equilibrium concentration | the actual concentration
🗑
|
||||
| density | m/v
🗑
|
||||
| molarity | moles solute/ L solution
🗑
|
||||
| molecular weight | molar mass ( mass of a molecule) calculated as the sum of the mass of each constituent atom multiplied by the number of atoms of that element in the molecular formula
🗑
|
||||
| weight percent | weight solute/ mL sample
🗑
|
||||
| qualitative analysis | identifying what is in an unknown
🗑
|
||||
| quantitative analysis | identifying how much is present
🗑
|
||||
| gravimetric analysis | mass of product is measured to determine how much unknown was present
🗑
|
||||
| analytical balance | measure to 4 decimal places
🗑
|
||||
| buret | used to titrate
🗑
|
||||
| desiccant | drying agent in dessicator
🗑
|
||||
| desiccator | closed chamber containing drying agent—to keep samples dried
🗑
|
||||
| direct weighing | place directly on balance
🗑
|
||||
| hygroscopic | absorbs/ attracts moisture from air
🗑
|
||||
| indirect weighing | weigh by difference—do not weigh onto balance
🗑
|
||||
| meniscus | curvature of liquid caused by surface tension
🗑
|
||||
| pipet | used to transfer known amount of liquid- can go to 4 s.f.
🗑
|
||||
| tare | 0 a balance
🗑
|
||||
| top-loading balance | measures to 2 decimal places
🗑
|
||||
| volumetric flask | calibrated to contain certain vol of liquid at 20 degrees celcius when bottom of meniscus in in the right spot
🗑
|
||||
| parallax error | error that occurs when your eye is not at the same height as the meniscus
🗑
|
||||
| accuracy | difference between delivered and desired volume
🗑
|
||||
| determinate error | repeatable if measurement made same way (correctable)
🗑
|
||||
| indeterminate error | (random error)- from experiment
🗑
|
||||
| precision | reproducibility of replicate deliveries
🗑
|
||||
| relative error relative uncertainty? | (Absolute uncertainty/magnitude of measurement)
🗑
|
||||
| relative precision (rsd) | measurement of how close measurements are to each other
🗑
|
||||
| systematic error | error in process or equipment
🗑
|
||||
| degrees of freedom | (n-1)
🗑
|
||||
| confidence interval | range of values in which there is a specified probability of finding the true mean
🗑
|
||||
| Gaussian distribution | characterized by a mean and standard deviation—mean is center of distribution and standard deviation is width (bell shaped curve)
🗑
|
||||
| standard devation | measure of width of distribution
🗑
|
||||
| relative standard deviation | std deviation devided by mean
🗑
|
||||
| pooled standard deviation | pooled standard deviation to make use of multiple sets of data
🗑
|
||||
| Grubbs test | test for an outlier
🗑
|
||||
| t statistic | ratio of the departure of an estimated parameter from its notional value and its standard error
🗑
|
||||
| p value | tells you if you can reject or accept your null hypothesis
🗑
|
||||
| F test | to test if variances from two things are equal
🗑
|
||||
| student’s t test | statistical tool used to express confidence intervals and to compare results from different experiments
🗑
|
||||
| variance | square of the standard deviation
🗑
|
||||
| back titration | excess of a standard reagent is added to analyte
🗑
|
||||
| blank titration | contains everything except the analyte helps us see titration error
🗑
|
||||
| end point | sudden change in physical property of solution
🗑
|
||||
| equivalence point | when the moles of titrant moles of analyte in their stoichiometric relationship
🗑
|
||||
| indicator | compound with a property that changes abruptly when titration is complete
🗑
|
||||
| primary standard | pure enough to weigh and use directly for number of moles
🗑
|
||||
| standard solution | solution containing known quantity of analyte
🗑
|
||||
| standardization | titrating to determine concentration of titrant
🗑
|
||||
| titrant | known reagent solution
🗑
|
||||
| titration | increments of a known reagent are added to the analyte
🗑
|
||||
| titration error | difference between endpoint and equivalence point
🗑
|
||||
| volumetric analysis | volume of known reagent required for complete reaction with analyte by a known reaction is measured
🗑
|
||||
| indicator error | dif btwn observed and true equivalence point
🗑
|
||||
| primary standard acids and bases | acid
🗑
|
||||
| KHP | bases
🗑
|
||||
| Na2CO3 and THAM |
🗑
|
||||
| Kjeldahl Nitrogen determination | one of the most widely used methods for determining
🗑
|
||||
| nitrogen in organic substances | the solid is digested in boiling sulfuric acid to convert nitrogen into ammonium
🗑
|
||||
| Chelate | compound containing a ligand (typically organic) bonded to a central metal atom at two or more points
🗑
|
||||
| complexometric titration | for of volumetric analysis in which the formation of a colored complex is used to indicate the endpoint of a titration
🗑
|
||||
| direct titration | way to determine the contents of a substance quantitatively
🗑
|
||||
| displacement titration | analyte is treated with excess of a second metal bound to EDTA. The analyte ion displaces the second metal from the EDTA complex
🗑
|
||||
| indirect titration | another name for a back titration
🗑
|
||||
| formation constant | equilibrium constant for reaction of a metal with a ligand. Also called stability constant
🗑
|
||||
| Lewis acid | electron pair acceptor
🗑
|
||||
| Lewis base | electron pair donors
🗑
|
||||
| Ligand | atom or group of atoms bound to whatever atom you are interested in
🗑
|
||||
| masking agent | prevents impurities from reacting with the precipitant
🗑
|
||||
| monodentate ligand | ligand that bonds to a metal through only one atom
🗑
|
||||
| multidentate ligand | binds to the metal ligand through more than one ligand atom
🗑
|
||||
| adsorption indicator | used in Fajans titration
🗑
|
||||
| argentometric titration | titrations iinvolving Ag+
🗑
|
||||
| Fajans titration | adsorption of a colored indicator on the precipitate at the end point
🗑
|
||||
| Mohr titration | determination of a chloride by precipitation titration with silver nitrate
🗑
|
||||
| Vollhard titration | formation of a soluble
🗑
|
||||
| iodimetry | when a reducing analyte is titrated wIth iodine
🗑
|
||||
| iodometry | titration Of iodine produced when oxidizing analyte is added to excess I-
🗑
|
||||
| Spectroscopy Absorbance | most useful quantitity for chemical analysis (A)—higher the absorbance
🗑
|
||||
| absorbance spectrum | graph showing how A (or epsilon) varies with wavelength
🗑
|
||||
| Beer's law | dependence on concentration and path length
🗑
|
||||
| calibration curve | absorbance at one wavelength is plotted against different concentrations in a series of standards
🗑
|
||||
| cuvet | cell which has flate
🗑
|
||||
| molar absorptivity | symbolized by epsilon
🗑
|
||||
| spectrophotometry | the use of electromagnetic radiation to measure chemical concentrations
🗑
|
||||
| transmittance | the fraction of incident light that passes through a sample TEquals(P/Po)
🗑
|
||||
| wavelength | crest- to- crest distance between waves
🗑
|
Review the information in the table. When you are ready to quiz yourself you can hide individual columns or the entire table. Then you can click on the empty cells to reveal the answer. Try to recall what will be displayed before clicking the empty cell.
To hide a column, click on the column name.
To hide the entire table, click on the "Hide All" button.
You may also shuffle the rows of the table by clicking on the "Shuffle" button.
Or sort by any of the columns using the down arrow next to any column heading.
If you know all the data on any row, you can temporarily remove it by tapping the trash can to the right of the row.
To hide a column, click on the column name.
To hide the entire table, click on the "Hide All" button.
You may also shuffle the rows of the table by clicking on the "Shuffle" button.
Or sort by any of the columns using the down arrow next to any column heading.
If you know all the data on any row, you can temporarily remove it by tapping the trash can to the right of the row.
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Created by:
jpf11230
Popular Chemistry sets