Saturday, March 21, 2009

Forensic scientist :)






My future career: Forensic Scientist.

Requirements: > complete the whole education course, must enter either JC/ Poly.
> PH.D in Chemistry
> Complete a forensic science course in the Faculty of Science in
National University of Singapore.
> At least a BSc (2nd upper Hons) in Chemistry, preferably with
physics and engineering sciences.
> A postgraduate degree (MSc, PhD)) in a relevant discipline or
working experience in a forensic laboratory is an advantage.
> Strong theoretical foundations and a good working knowledge of
general chemistry and instrumental techniques in the identification
and characterisation of materials.
> Proficiency in written and oral communication is required as there
is a requirement to routinely write reports on forensic findings and
present expert testimony in Court.

My Responsibility :
I will join a team of forensic scientists in the Forensic Physics and Chemistry Laboratory examining a wide range of physical evidence. i would have to trace evidence (glass, arson, paints, soils, fibres), unknown organic and inorganic substances, fire and explosion debris, firearms components, marks and prints and bloodstain patterns.I am also expected to work independently as well as in a team.
I must have a strong passion for science, good bench skills and highly developed skills in logical reasoning, problem solving and critical thinking. Error-free, quality work and sound conclusions that can withstand Court scrutiny are expected for every case I handle.

What i would be covering during my job :

Forensic Chemistry and Physics Laboratory services are built around HSA's core strengths in identifying microscopic or trace level amounts of material in complex mixtures, and in comparing marks, prints and patterns. Forensic Chemistry and Physics Laboratory is Singapore's national laboratory for the integrated forensic examination of the following types of physical evidence:

> Fire and explosions
> Chemical analysis and trace evidence
> Marks, impressions and physical examinations
> Scene analysis and reconstruction
> Research and commercial cases

As Analysts gazetted under the Health Sciences Authority Act, Forensic Chemistry and Physics Laboratory (FCPL) scientists provide prima facie evidence and expert testimony in Singapore Courts.

FCPL also provides an extensive range of services on the examination of handwriting, signatures, ink, paper and printersencountered in criminal investigation and civil disputes. Our clients include law enforcement agencies such as Singapore Police Force and private individuals and organizations such as law firms and banks.

The laboratory is one of the few worldwide qualified to examine both English and Chinese handwriting and signatures. The officers have rendered services to many countries comprising Hong Kong, United States of America, Australia, Germany, Brunei and Malaysia.

HSA's research works are well-received in international conferences, and some of them are published in peer-reviewed journals.

I would also have to:

> Examination of handwriting and signatures in English, Chinese and romanized scripts;
> Examination of tampered and counterfeit documents;
> Differentiation of inks;
> Chemical analysis of paper and inks;
> Visualisation of indented writing;
> Identification of rubber stamps and rubber stamp impressions;
> Determination of the sequence of two intersecting lines;
> Physical fitting of torn/cut documents;
> Examination of photocopies and facsimile documents;
> Examination of typewritten and computer printed documents;
> Conducting lectures, seminars and training sessions for interested parties

Friday, March 20, 2009

EnDpOiNt AnD eQuIvAlEnCe PoInT.

End point of a titration can be measured in many ways.
Some of which are by using:
- pH indicator: This is a substance that changes colour in response to a chemical change. An acid-base indicator (e.g., phenolphthalein) changes colour depending on the pH.
- A potentiometer can also be used. This is an instrument that measures the electrode potential of the solution.
- pH meter: This is a potentiometer that uses an electrode whose potential depends on the amount of H+ ion present in the solution
- Colour change: In some reactions, the solution changes colour without any added indicator.


Difference between endpoint and equivalence point:

Equivalence Point: Equivalence-point means the moment in your slow, dripping addition,at which the amount of base added is chemically equivalent to the acid in the flask, (or vice-versa) so the two kinds of reagent are exactly cancelling out.

Endpoint: the end-point is the perceptual event at which the indicator actually does change, and you decide you are "done", and you actually read the quantity of measuring reagent you have added. Such as when the solution finally changes colour and does not change back right away.

Monday, March 2, 2009

Moles :)

i have learnt a lot about mole concept during chemistry lesson today. i am also able to see how concentration, mass, volume and Avogadro's Constant are connected to moles.

To calculate moles, i can use many formulas. Some examples are:

1. mole = mass/ Mr
2. mole= concentration/ volume
3. mole= no. of particles/ Avogadro's Constant.


i also learnt how to find Ar by this formula:

I and Y are isotopes of an element.

Ar= ( relative isotopic mass of I x % abundance of I) + ( relative isotopic mass
of substance Y x % abundance of substance Y) / 100