P&R Labpak - Everything for your laboratory

P&R Labpak - Everything for your laboratory
Our Head Office in St Helens

Friday, 19 September 2014

Sodium Hypochlorite


Sodium hypochlorite is a chemical compound with the formula NaClO. It is composed of a sodium cation (Na+) and a hypochlorite anion (ClO−); it may also be viewed as the sodium salt of hypochlorous acid. When dissolved in water it is commonly known as bleach or liquid bleach, and is frequently used as a disinfectant or a bleaching agent.


Click to enlarge


Potassium hypochlorite was first produced in 1789 by Claude Louis Berthollet in his laboratory on the quay Javel in Paris, France, by passing chlorine gas through a solution of potash lye. The resulting liquid, known as "Eau de Javel" ("Javel water"), was a weak solution of potassium hypochlorite. Antoine Labarraque replaced potash lye by the cheaper soda lye, thus obtaining sodium hypochlorite (Eau de Labarraque).

Various methods have been used since to produce this but the modern method, the Hooker process, is the only one producing this in any bulk capacity.

Sodium Hypochlorite has many uses as can be seen above:-


In bleach cleaning products and to remove stains.
In Swimming pools as a disinfectant.
In Antibacterial sprays
To neutralise nerve agents
To reduce skin damage - using very low concentrations.

Sodium Hypochlorite although used in household bleach is not the only component.  There is often Sodium Hydroxide and Calcium Hypochlorite amongst others.  it must be remembered not to mix household cleaning products as some may contain hydrochloric acid. If these are mixed with bleach, it can react with sodium hypochlorite, and form toxic chlorine gas

Visit the following for more information:-
http://www.compoundchem.com/2014/07/06/sodium-hypochlorite-bleach-swimming-pools-cleaning-products/
http://en.wikipedia.org/wiki/Sodium_hypochlorite

Friday, 12 September 2014

Mercury


Mercury is a chemical element with the symbol Hg and atomic number 80. It is commonly known as quicksilver and was formerly named hydrargyrum (from Greek "hydr-" water and "argyros" silver)

 
 
Mercury is remarkable because it is the only metal that is liquid at room temperature. It is a dense, lustrous grey metal. Mercury is extremely rare in the Earth's crust and in the wild, it typically is concentrated near volcanically active areas, either as the pure metal or in a number of minerals.
 
Mercury is used in thermometers, barometers, manometers, sphygmomanometers, float valves, mercury switches, mercury relays, fluorescent lamps and other devices, though concerns about the element's toxicity have led to mercury thermometers and sphygmomanometers being largely phased out in clinical environments in favour of alternatives such as alcohol- or galinstan-filled glass thermometers and thermistor- or infrared-based electronic instruments.
The reason mercury was so popular is because it readily forms stable amalgams with a number of other metals, particularly silver and gold, making them workable at lower temperatures, and these amalgams have been the source of many instances of mercury poisoning.
Amalgam Filling
 
Biologists are quite interested in mercury because it is highly toxic to life, causing both acute and chronic poisoning. Mercury can be absorbed through the skin and mucous membranes and mercury vapors can be inhaled. Mercury is concentrated in the body over the lifetime of the individual, and it also becomes more concentrated when one animal eats another, which is how it moves up the food chain. This is the reason why the flesh of tuna, a long-lived apex predator in the oceans, contain such high levels of mercury.
For more information visit:-


Friday, 5 September 2014

Back to school

Where did the summertime break go?  Time for kids to go back to school.  And time for us too...chemistry basics.....Acids and bases

All acids:
  • have a low pH (1-6) – the lower the number the stronger the acid
  • react with bases to form neutral compounds
  • are corrosive when they are strong
  • are an irritant when they are weak.
Acids have a pH of less than 7. Bases have a pH of more than 7. When bases are dissolved in water, they are known as alkalis. Salts are made when an acid reacts with a base, carbonate or metal. The name of the salt formed depends on the metal in the base and the acid used. For example, salts made using hydrochloric acid are called chlorides.


Acids
Substances with a pH of less than 7 are acids. The more strongly acidic the solution, the lower its pH number. Acidic solutions turn blue litmus paper red. They turn universal indicator paper red if they are strongly acidic, and orange or yellow if they are weakly acidic.

Bases
Substances that can react with acids and neutralise them to make a salt and water are called bases. They are usually metal oxides or metal hydroxides. For example, copper oxide and sodium hydroxide are bases.

Alkalis
Bases that dissolve in water are called alkalis. Copper oxide is not an alkali because it does not dissolve in water. Sodium hydroxide is an alkali because it does dissolve in water.

Alkaline solutions have a pH of more than 7. The stronger the alkali, the higher the pH number. Alkalis turn red litmus paper blue. They turn universal indicator paper dark blue or purple if they are strongly alkaline, and blue-green if they are weakly alkaline.

Neutral solutions
Neutral solutions have a pH of 7. They do not change the colour of litmus paper, but they turn universal indicator paper green. Water is neutral.

For pH meters or pH test papers or buffer solutions give us a call.

For more information visit:-
http://www.prlabs.co.uk
http://en.wikipedia.org/wiki/PH

Friday, 29 August 2014

Red hot chilli peppers!!!

The chilli pepper or chilli is the fruit of plants from the genus Capsicum.  The substances that give chili peppers their intensity when ingested or applied topically are capsaicin (8-methyl-N-vanillyl-6-nonenamide) and several related chemicals, collectively called capsaicinoids.
Cayenne pepper

Chili peppers originated in the Americas but spread around the world and India is now the world's largest producer, consumer and exporter of chili peppers.

When consumed, capsaicinoids bind with pain receptors in the mouth and throat that are responsible for sensing heat. Once activated by the capsaicinoids, these receptors send a message to the brain that the person has consumed something hot. The brain responds to the burning sensation by raising the heart rate, increasing perspiration and release of endorphins.

The "heat" of chili peppers was historically measured in Scoville heat units (SHU), which is a measure of the dilution of an amount of chili extract added to sugar syrup before its heat becomes undetectable to a panel of tasters; the more it has to be diluted to be undetectable, the more powerful the variety and therefore the higher the rating.  The modern commonplace method for quantitative analysis of SHU rating uses high-performance liquid chromatography to directly measure the capsaicinoid content of a chili pepper variety. Pure capsaicin is a hydrophobic, colorless, odorless, and crystalline-to-waxy solid at room temperature, and measures 16,000,000 SHU.


Chemistry of a Chilli-click to enlarge


Capsaicin extracted from chillis is also used in pepper spray as an irritant, a form of less-lethal weapon.

Red chilies contain large amounts of vitamin C and small amounts of carotene (provitamin A). Yellow and especially green chilies (which are essentially unripe fruit) contain a considerably lower amount of both substances. In addition, peppers are a good source of most B vitamins, and vitamin B6 in particular. They are very high in potassium, magnesium, and iron. Their very high vitamin C content can also substantially increase the uptake of non-heme iron from other ingredients in a meal, such as beans and grains.

For more information visit:-
http://www.compoundchem.com/2014/01/15/why-chilli-peppers-are-spicy-the-chemistry-of-a-chilli/
http://en.wikipedia.org/wiki/Chilli_pepper

Friday, 22 August 2014

Hayfever!!!

It's still summer - or at least it was sunny when I wrote this.  Knowing the British weather it could be raining now.  However rain doesn't always stop the effects of hayfever.

Pollen

Allergic rhinitis is an allergic inflammation of the nasal airways. It occurs when an allergen, such as pollen, dust or animal dander (particles of shed skin and hair) is inhaled by an individual with a sensitized immune system. In such individuals, the allergen in affected individuals is mistakenly identified as a threat and triggers the production of the antibody immunoglobulin E (IgE), which binds to mast cells and basophils containing histamine. When caused by pollens of any plants, it is called pollinosis, and, if specifically caused by grass pollens, it is known as hay fever. While symptoms resembling a cold or flu can be produced by an allergic reaction to pollen from plants and grasses it does not cause a fever.


IgE bound to mast cells are stimulated by allergens, causing the release of inflammatory mediators such as histamine (and other chemicals). This usually causes sneezing, itchy and watery eyes, swelling and inflammation of the nasal passages, and an increase in mucus production.
To reduce the symptoms of hayfever science has developed a number of medications to alleviate or prevent the symptoms.  A fantastic website (Compound Interest) goes into this in much more detail including the amazing infographic below.

http://www.compoundchem.com/wp-content/uploads/2014/06/Chemistry-Hayfever-Hayfever-Medications.png
Click to enlarge

Antihistamine drugs include those such as cetirizine and loratadine. They work by binding to the H1 receptors that histamine usually binds to, preventing it from inducing an inflammatory response to the allergens.  As you can see from the infographic above some drugs must be taken before symptoms appear for them to be effective.  Click here for a full screen image.

For more information visit:-
http://www.compoundchem.com/2014/06/20/hayfever/
http://en.wikipedia.org/wiki/Hayfever

Friday, 15 August 2014

What is Brownian Motion?

The term 'Brownian motion' (or 'Brownian movement') refers to the apparently random, haphazard movement of microscopic particles which are suspended in a fluid - (a liquid or a gas) resulting from their collision with the quick atoms or molecules in the gas or liquid.

This is a simulation of the Brownian motion of a big particle (dust particle) that collides with a large set of smaller particles (molecules of a gas) which move with different velocities in different random directions.
Although a number of earlier workers had observed this phenomenon, it was first described, and therefore named after, the British botanist, Robert Brown, who was studying pollen grains in 1827. Brown was an accomplished microscopist. It was he who, for example, first identified the naked ovule in the gymnospermae; this is a difficult observation to make even with a modern instrument.

Brown was attempting to further his work on the mechanisms of fertilisation in flowering plants and was looking at pollen.  He believed that he would be able to examine the pollen grains more effectively through his microscope if they were suspended in water, a technique known as 'water-immersion'. To his annoyance, he observed that the pollen grains danced continuously and erratically around in the water, thus interfering with his observations. From these observations he satisfied himself that the movement:

'arose neither from currents in the fluid, nor from its gradual evaporation, but belonged to the particle itself'.

Decades later, Albert Einstein published a paper in 1905 that explained in precise detail how the motion that Brown had observed was a result of the pollen being moved by individual water molecules.

Despite all of this knowledge, scientists continue to be fascinated by the origin and nature of Brownian motion, which is still imperfectly understood. Articles concerning the mathematics of Brownian motion continue to be published in contemporary physics journals.

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

Friday, 8 August 2014

1000mph - along the ground - Bloodhound SSC.

BLOODHOUND SSC is a SuperSonic Car.  It's supersonic because it is designed to go faster than the speed of sound and it's a car because it has four wheels and is under full control of its driver.

BLOODHOUND SSC is a jet and rocket powered car designed to go at 1,000 mph (just over 1,600 kph). It has a slender body of approximately 14m length with two front wheels within the body and two rear wheels mounted externally within wheel fairings. It weighs over 7 tonnes and the engines produce more than 135,000 horsepower - more than 6 times the power of all the Formula 1 cars on a starting grid put together!

The Car is a mix of car and aircraft technology, with the front half being a carbon fibre monocoque like a racing car and the back half being a metallic framework and panels like an aircraft.

Runway testing of up to 200 miles per hour (320 km/h) is scheduled to take place early 2016. Bloodhound SSC will then be tested on the Hakskeen Pan in the Mier area of the Northern Cape, South Africa where a track 12 miles (19 km) long, 2 miles (3.2 km) wide has been cleared.

The car is an amazing feat of engineering.  A prototype Eurojet EJ200 jet engine developed for the Eurofighter and bound for a museum, was donated to the project. This will take the car to 300 mph (480 km/h), after which a bespoke hybrid rocket designed by Nammo will boost the car up to 1,000 miles per hour (1,609 km/h). A third engine, a 750 hp (560 kW) 2.4 Litre Cosworth CA2010 Formula 1 V8 petrol engine, is used as an auxiliary power unit and to drive the oxidiser pump for the rocket. The jet engine will provide nine tonnes of thrust and the rocket will add another 12. The supersonic car will have roughly the same power as 180 F1 cars.

The Bloodhound SSC project has a comprehensive website as below:-
http://www.bloodhoundssc.com/project/car

They are on Twitter and regularly post updates.  An example is the fascinating infographic below - 10 astounding facts about Bloodhound SSC.

Be sure to keep up to date and follow the Bloodhound SSC project.
http://www.twitter.com/BLOODHOUND_SSC
http://www.facebook.com/BLOODHOUNDSSC