1. QUESTIONS
Q: What is analytical chemistry?
A: Analytical chemistry is the science of obtaining, processing,and
communicating information about the compositionand structure of
matter. In other words, it is the art and science of determining what
matter is and how much of it exists.
Q: what are the examples of analytical chemistry?
A: For example, gas chromatography-mass spectrometry,gas
chromatography-infrared spectroscopy,liquid chromatography-mass
spectrometry,liquid chromatography-NMR spectroscopy.liquid
chromatography-infrared spectroscopyand capillary electrophoresis-
mass spectrometry.
Q: what Is quality control?
A: Quality control (QC) is a processthrough which a business
seeks to ensurethat productquality is maintainedor improved.
Quality control involves testing units and determining if they are within
the specifications forthe final product.
Q: What is Quality assurance?
A: Quality assurance (QA) refers to the full range of practices
employed to ensure that laboratory results are reliable. ... Quality
assurance may be defined as the system of documenting and cross
referencing the management procedures ofthe laboratory.
Q: What are the types of burrets?
A: There are two main types of burette; the volumetric burette and the
Piston burette or Digital burette. A volumetric burette delivers
measured volumes of liquid. Piston burettes are similar to syringes,
but with a precisionbore and a plunger. Piston burettes may be
manually operated or may be motorized.
Q: What is the type of pippete?
A: The five grades of pipettes include disposable/transfer,
graduated/serological,single-channel, multichannel, and repeat
pipette.
2. Q: Define example of random errror?
A:One of these is called Random Error. An error is considered
random if the value of what is being measured sometimes goesup or
sometimesgoes down. A very simple example is our blood pressure.
Even if someone is healthy, it is normal that their blood pressure does
not remain exactly the same every time it is measured.
Q: What is the difference betweenthe QA and software testing?
A: The role of QA (Quality Assurance) is to monitor the quality of the
“process”used to produce the software. While the software testing, is
the process of ensuring the functionality of final product meets the
user’s requirement.
Q: What are the 3 main objectives of quality control?
A: Main objectives of quality control: enhance productquality and
reduce risks, gain productionefficiencies,and garner customer
loyalty.
Q: What's the difference betweenquality control and quality
assurance?
A: Quality control can be defined as "part of quality management focused
on fulfilling quality requirements." While quality assurance relates to how a
process is performed orhow a product is made, quality control is more the
inspectionaspectof quality management.
Q: Define error and also write its types?
A: The numerical differences betweenmeasured value and absolute value
of an analytical determination. There are two major types of error.
i. Systematic errors
ii. Random errors
Q: Define Systematic error?
A: It is also called determinate error.
It is consistent error that can be detected and corrected.
It is unidirectional
3. Example:pH meter that has beenstandardized incorrectly. When we use
pH meter that has beenstandardized incorrectly will give incorrect result
due to determinate error.
Q: Define instrumental error?
A: The error which arises from the imperfections in measuring devices
(pipettes and measuring flasks).
To remove this error we calibrate the instrument and then do experiment.
It is also called weighing error.
Q: What are the ideal conditions for Precipitation?
All precipitation gravimetric analysis shares two important
attributes.
First, the precipitate must be of low solubility, of high purity,
and of known compositionif its mass is to accurately reflectthe
analyst’s mass.
Second,the precipitate must be easy to separate from the
reaction mixture.
Size of crystal must be larger.
Q: What are the types of contaminations in precipitation?
Precipitationis a type of precipitation where soluble
compounds in a solution are removed during the course of
precipitation.
Post precipitation is the precipitation of a second,often
related, substance upon the surface of an initial precipitate.
Q: What type of filter media is good for filtration?
The filter media used in industry and in laboratory practice
should have the following properties:
an appropriate porosity(that is, the pores should be of such a
size that the particles of the filter cake are trapped in the filter
medium
4. chemical resistance to the filtrate;
sufficientmechanical strength
Q: What do you about accuracy?
A: In a set of measurements,accuracy is closeness of the measurements
to a specific value, while precisionis the closeness ofthe measurements to
each other.
Accuracy has two definitions:
More commonly,it is a descriptionof systematic errors, a measure of
statistical bias; low accuracy causes a difference betweena result and a
"true" value. ISO calls this trueness.
Q: what is quantification?
A: A reading of 8,000 m, with trailing zeros and no decimal point, is
ambiguous; the trailing zeros may or may not be intended as significant
figures.To avoid this ambiguity, the number could be represented in
scientific notation: 8.0 × 103 m indicates that the first zero is significant
(hence a margin of 50 m) while 8.000 × 103 m indicates that all three zeros
are significant, giving a margin of 0.5 m. Similarly, one can use a multiple of
the basic measurementunit: 8.0 km is equivalent to 8.0 × 103 m. It
indicates a margin of 0.05 km (50 m). However, reliance on this convention
can lead to false precisionerrors when accepting data from sources that do
not obey it. For example, a source reporting a number like 153,753with
precision+/- 5,000 looks like it has precision+/- 0.5. Under the convention
it would have been rounded to 154,000.
Q: How do we take readings on pipette?
A: In a way, pipettes work a lot like drinking straws in that they allow liquids
to be 'sucked-up' into one end. They are used to accurately measure and
transfer small volumes of liquids.
Though they may work like drinking straws, never use your mouth to suck-
up liquids into a pipette! Instead use a pipette-aide as described below.
Pipette-aides or pipetts are suction devices that are used to either suck
liquids into or expel liquids out of pipettes. For some types of
5. measurement it may be necessary to expel, or blow-out, the total liquid
volume from the pipette using the pipette-aid.
Types of Pipette-Aids.a. Least expensive type of bulb; not easily
controlled.b. A pipette pump that can be used to take up and expel liquid.
c. More expensive bulbs allow fine control of liquid. This type of pipette aid
may be called a "triple valve" device because it has three buttons: The first
displaces air from the bulb, the second is used to draw liquid into the
pipette,and the third is used to expelthe liquid. d. Electronic pipette aid
that allows fine control and ease of use.
Q: What is filtration?
A: Filtration, the process inwhich solid particles in a liquid or gaseous fluid
are removed by the use of a filter medium that permits the fluid to pass
through but retains the solid particles. Either the clarified fluid or the solid
particles removed from the fluid may be the desired product.In some
processesused in the productionof chemicals,both the fluid filtrate and the
solid filter cake are recovered.Other media, such as electricity, light, and
sound, also can be filtered.
Q: What is the example of filtration?
A: The most commonexample is making tea. While preparing tea, a filter or
a sieve is used to separate tea leaves from the water. Through the sieve
pores,only water will pass.The liquid which has obtained after filtration is
called the filtrate; in this case, water is the filtrate.
Q: What is filter media?
A: Filter media may be divided into two general classes:(1) thin barriers,
exemplified bya filter cloth, filter screen,or commonlaboratory filter paper;
(2) thick or masse barriers, such as sand beds,coke beds,porous
ceramics,porous metal, and the pre coat of filter aid which is oftenused in
the industrial filtration of fluids that contain gelatinous precipitates.
Q: What is ignition?
A:ignition is a test used in inorganic analytical chemistry, particularly in the
analysis of minerals. It consists of strongly heating ("igniting") a sample of
the material at a specified temperature,allowing volatile substances to
escape,until its mass ceases to change