Introduction Flashcards
It is a measurement science consisting of a set of powerful ideas and methods that are useful in all fields of science and medicine
Analytical Chemistry
Reveals the identity of elements and compounds in a sample
Qualitative
Indicates the amount of each substance in a sample
Quantitative
Components of a sample that are to be determined
Analytes
Results of a typical quantitative analysis are computed from two measurements:
- Mass or the volume
2. Quantity that is proportional
These are Quantity that is proportional
Mass, volume, intensity of light, electrical charge
Analytical method according to mass of the analyte or some compound chemically related to it
Gravimetric
Analytical method according to the nature of the volume of a solution containing suffcient reagent to react completely with the analyte
Volumetric Method
Analytical method which invloves electrical properties such as voltage, current, resistance and quantity of electrical charge
Electroanalytical methods
Analytical method that is based
Measurement of the interaction between electromagnetic radiation and analyte atoms
Spectroscopc Method
In the flow diagram showing the steps in a quantitative analysis:
What happens when the sample is soluble?
Proceed to the question: is it measurable property
In the flow diagram showing the steps in a quantitative analysis:
What should you do if the property of sample is measurable?
Eliminate interferences
In the flow diagram showing the steps in a quantitative analysis:
What should you do if the sample is not soluble ?
Carry out chemical dissolution
In the flow diagram showing the steps in a quantitative analysis:
What should you do after you carry out chemical dissolution?
Know whether is it a measurable property
In the flow diagram showing the steps in a quantitative analysis:
What should you do if the property of sample is not measurable?
Change the chemical form then eliminate the interferences
These are the first 3 steps in the flow diagram showing the steps in a quantitative analysis
Select method
Acquire sample
Process sample
It is the first question to be considered in the selection process of picking a method
Level of accuracy is required
In picking a method, It is the second consideration related to economic factors.
Number of samples to be analyzed
It influences the choice of method to some degree in picking a method
Complexity of the sample and the number of components in the sample
It invloves obtaining a small mass of material whose composition accurately represents the bulk of the material being sampled
Sampling
The most difficult step in an analysis and it is the source of greatest error
Sampling
A material is known as _________ if its constituent parts can be distinguished visually or the aid of a microscope
Heterogenous
It is the process of determining how much of a given sample is the material indicated by its name
Assay
We analyze________ and we determine _____________
Sample and substances
No sample processing is required prior to the ______________ step
Measurement
We must process the sample in _______________ ways
Variety of different
A solid sample is _______ and ______ to ensure homogeneity
Ground and mixed
Sample should be ________for various length of time before analysis begins
Stored
Because of loss or gain of water it changes the composition of solids, it is a good idea to _______ samples before starting an analysis
Dry
The ___________of the sample can be determined at the time of the analysis in a separate analytical procedure
Moisture content
Liquid samples are subject to ______________
Solvent evaporation
If the analyte is a gas dissolved in liquid, analyte must be kept inside __________________ to prevent contamination by ___________________ gases
Second sealed, atmospheric
Extraordinary measures, including sample manipulation and measurement in an inert atmosphere, may be required to preserve the _____________ of the sample
Integrity
Portions of a material of approximately the same size carried through analytical procedure at the same time and same way
Replicate samples
Provides reliability of the experiment and it has atleast 3 same results
Replicate sample
Replication improves what?
Quality of result and reliability
How does a solvent disolve the entire sample including the analyte
Rapidly and completely
The sample may require ___________ with aquaous solution
Heating
It may be necessary to _______ the sample in all or oxygen to perform a high-temperature fusion of the sample in the presence of various fluxes
Ignite
Species other than the analyte that affect the final measurement is called?
Interferences or interferents
Species that cause an error in analysis by enhancing or attenuating the quantity being measured
Interference
Tecniques or reaction that work for only one analyte are said to be _________
Specific
Techniques or reactions that apply for only a few analytes are____________
Selective
It is all of the components in the sample containing analyte
Matrix or sample matrix
Measurement of the property is ___________ to the concentration
Directly proportional
Process of determining the proportionality between analyte concentration and a measured quantity
Calibration
Computing analyte concentrations are based on
Raw experimental data
Where can you collect raw experimental data?
Measurement step, instruments and stoichiometry of the reaction
The analytical results are incomplete without an estimate of ________
Reliability
Analytical results without an estimate of reliabilty is
No value
It is the first step in a feedback control system
Start control system
After you start the contro system what should you determine?
Desired state or the normal values
After you determine the desired state what should you do?
Measure the actual state
After measuring the actual state what should you do?
Display results
After displaying the results what should you do next?
Verify if the desired state actual
If the desired state is actual what shoul you do next?
Delay, try to make sure that it works
If the desired state is not actual what should you do?
Repeat the process and change control quantity
Process of continous measurement and control
Feedback system
Cycle of measurement, comparison and control
Feedback loop
Standardized system of unit
International System of Units (SI)
SI is the acronym for the french word?
Systeme international d’unites
This unit is widely used to express wavelength
Angstrom
Number of moles of solute species in one liter of solution
Molar concentration
Dimension of molarity
Mol L^-1
Gives the total number of moles of a solutein 1L of the solution
Analytical molarity
Express the molar concentration of a paricular species in a solution
Equilibrium molarity
