Titration

Titration, also known as titrimetry, is a common laboratory method of quantitative chemical analysis that is used to determine the unknown concentration of an identified analyte. Since volume measurements play a key role in titration, it is also known as volumetric analysis. A reagent, called the titrant or titrator is prepared as a standard solution. A known concentration and volume of titrant reacts with a solution of analyte or titrand to determine concentration.

Titrator set up

 
The word "titration" comes from the Latin word titulus, meaning inscription or title. The French word titre, also from this origin, means rank.
 

There are several reasons why titration is used in laboratories worldwide:

1. Titration is an established analytical technique
2. It is fast
3. It is a very accurate and precise technique
4. A high degree of automation can be implemented
5. Titration offers a good price/performance ratio compared to more sophisticated techniques
6. It can be used by low-skilled and low-trained operators
7. No need for highly specialised chemical knowledge

Karl Fischer titration: A potentiometric method to analyse trace amounts of water in a substance. A sample is dissolved in methanol, and titrated with Karl Fischer reagent. The reagent contains iodine, which reacts proportionally with water. Thus, the water content can be determined by monitoring the potential of excess iodine.

 

Automated titrators follow a defined sequence of operations. This sequence is basically the same for all different models and brands. This sequence is performed and repeated several times until the endpoint or the equivalence point of the titration reaction is reached (titration cycle).

More complex applications require more steps, for example dispensing of an additional reagent for back titration, dilution of the sample, adjustment of the initial pH value, etc. These steps and the corresponding parameters are defined in the titration methods used by the titrator.


P&R Labpak offer a full range of titration equipment and associated consumables and chemicals such as Hydranal^® reagents.

For more information visit:-
http://en.wikipedia.org/wiki/Titration

On this day - April 11th 1970

Apollo 13 was launched on April 11, 1970, at 13:13 CST from the Kennedy Space Centre, Florida.  It was the seventh manned mission in the American Apollo space program and the third intended to land on the Moon. The lunar landing was aborted after an oxygen tank exploded two days later, crippling the Service Module (SM) upon which the Command Module (CM) depended. Despite great hardship caused by limited power, loss of cabin heat, shortage of potable water, and the critical need to jury-rig the carbon dioxide removal system, the crew returned safely to Earth on April 17.

Apollo 13 launches from Kennedy Space Center, April 11, 1970

A film was made regarding the Apollo 13 mission in 1995 directed by Ron Howard who went to great lengths to create a technically accurate movie, employing NASA's technical assistance in astronaut and flight controller training for his cast, and even obtaining permission to film scenes aboard a reduced gravity aircraft for realistic depiction of the "weightlessness" experienced by the astronauts in space.

Three days into the mission, the crew send a live television transmission from Odyssey, but the networks, believing the public now regards lunar missions as routine, decline to carry the broadcast live. Astronaut Swigert is told to perform a standard housekeeping procedure of stirring the two liquid oxygen tanks in the Service Module. When he flips the switch, one tank explodes, emptying its contents into space and sending the craft tumbling. The other tank is soon found to be leaking, prompting Mission Control to abort the Moon landing.

The crew is soon subjected to freezing conditions.  When the carbon dioxide exhaled by the astronauts reaches the Lunar Module's filter capacity and approaches dangerous levels, an engineering team quickly invents a way to make the Command Module's square filters work in the Lunar Module's round receptacles.  The crew eventually get the Odyssey going and make a safe return to earth.

The Apollo 13 Command Module

The Apollo 13 incident gave rise to the famous line 'Houston, We've Got a Problem'.

Further Apollo missions continued which resulted in successful manned landings on the moon.  There are a number of proposed future missions to the moon - most of them robotic or remote missions using rovers.  However the Russians did announce in 2007 their intention to send cosmonauts to the moon by 2025 and establish a permanent robotically operated base there in 2027–2032.

For more information visit:-

http://en.wikipedia.org/wiki/Apollo_13

Kevlar

Kevlar® is the registered trademark for a para-aramid synthetic fiber, related to other aramids such as Nomex and Technora. Developed by Stephanie Kwolek at DuPont in 1965, this high strength material was first commercially used in the early 1970s as a replacement for steel in racing tires. Typically it is spun into ropes or fabric sheets that can be used as such or as an ingredient in composite material components.

Kevlar® is a material formed by combining para-phenylenediamine and terephthaloyl chloride. Aromatic polyamide (aramid) threads are the result. They are further refined, by dissolving the threads and spinning them into regular fibres. When woven, Kevlar® forms a strong and flexible material. If layers of the woven Kevlar® are combined with layers of resin, the resulting ‘rigid’ material is light and has twenty times the strength of steel. It is also superior to specialist metal alloys. However, Kevlar® is expensive due to the demands of the manufacturing process and the need for specialist equipment.

Currently, Kevlar® has many applications, ranging from bicycle tires and racing sails to body armor because of its high tensile strength-to-weight ratio; by this measure it is 5 times stronger than steel on an equal weight basis.

Aramid Fibre

Kevlar® is a well-known component of personal armour such as combat helmets, ballistic face masks, and ballistic vests. Other military uses include bulletproof facemasks used by sentries and spall liners used to protect the crews of armoured fighting vehicles.  Emergency Service's protection gear also uses Kevlar® sometimes if it involves high heat (e.g., tackling a fire), and Kevlar® body armour such as vests for police officers.

Bullet Proof vests

 

Kevlar® is used to manufacture gloves, sleeves, jackets, chaps and other articles of clothing designed to protect users from cuts, abrasions and heat. Kevlar® based protective gear is often considerably lighter and thinner than equivalent gear made of more traditional materials.

For more information visit:-

http://en.wikipedia.org/wiki/Kevlar

http://h2g2.com/edited_entry/A791291

http://www.dupont.co.uk/products-and-services/fabrics-fibers-nonwovens/fibers/brands/kevlar.html

http://www.technologystudent.com/joints/kevlar2.html