Write A Chemistry Essay

[Keikan]

My homework is something to do with some unknown story called "Leiningen VS the ants"

[RedRival]

no essays???

[Pitbul]

i got a bong that can test physics. B)

[Yogi]

Arrhenius's ideas moved our understanding of acids and bases forward a long way, but there was one major problem with the ideas. They depended on all acid/base reactions taking place in solution in water - which course they don't. The reaction between hydrochloric acid and ammonia gas is a very good example of a neutralisation reaction which does not take place in water. In 1923 two different scientists, working quite independently, came up with an identical explanation for the behaviour of acids and bases Named after Johannes Nicolaus Brønsted (1879 - 1947) and Thomas Martin Lowry (1874 - 1936), the Brønsted-Lowry theory describes acids and bases in terms of the transfer of a proton from the acid to the base. They simply defined an acid as any ion or molecule able to produce a proton, while a base is any ion or molecule able to take up a proton. Their ideas did not conflict with what Arrhenius had said, but they took the model further forward. The Brønsted-Lowry theory explained reactions which Arrhenius's model could not. The new model was rapidly accepted and used by scientists - Brønsted and Lowry did not have the long wait for acceptance that Arrhenius had had to put up with.

Thomas Martin Lowry was the son of a Wesleyan army chaplain from Bradford in England. He was educated at the Central Technical College (which later became part of Imperial College), London, where from 1896 to 1913 he served as assistant to Henry Armstrong. From 1904 he was also head of chemistry at Westminster Training College until he moved to Guy's Hospital, London, in 1913 to become head of the Chemistry Department. In 1920 he was appointed as the first professor of physical chemistry at Cambridge University.

The son of a civil engineer, Johannes Nicolaus Brønsted was born on February 22nd, 1879 in Varde, a small town in West Jutland. His mother died soon after his birth, and his father remarried. However, when Johannes was only 14 years old his father died as well and he had to leave the farm where he had been brought up. Brønsted and his sister moved to Copenhagen with their stepmother and he attended the 'Metropolitanskolen' for three years . He passed his 'studentereksamen' (University entrance examination) in the summer of 1897.In the autumn of 1897 Brønsted took up studies at the (old) Polytecnic Institute in the street Sølvgade in Copenhagen. He completed his first degree studies in engineering in 1899, and began studies in pure science at Copenhagen University. He took his 'magister' degree in Chemistry in 1902.

At the Polytecnic Institute Brønsted met Charlotte Louise Warberg, who in 1902 became one of the very first female engineers in Denmark. They were married in 1903 and moved into a flat at Forchhammersvej in Copenhagen, and went on to have several children. There was no academic position immediately available for Brønsted in 1902 and it was three years before he could return to the University Chemical Laboratories to take up a position as an assistant. However, he was obviously very talented and from 17 December 1908 he was made professor.

In 1923, within several months of each other, Johannes Nicolaus Brønsted (Denmark) and Thomas Martin Lowry (England) published essentially the same theory about how acids and bases behave. Since they came to their conclusions independently of each other, both names have been used for the in naming the theory.

2NO2(g) -----> 2NO(g) + O2(g)

[james_bond_rulez]

this is an easy one:

Arrhenius and Ostwald defines acids as hydrogen-containing compound, meaning when you put the compound in water, it's dissociate into hydrogen ions. Bases are defined as compounds that contain hydroxyl ions, producing OH- when dissolved in water. acidic solution being the concentration of hyrogen ions is greater than the hydrogen ions produced by water (we all know that water dissociates and produced equal amount of H+ and OH- until reaches equalibrium). and basic solutions being number of OH- discociated by the compound greater than water produces OH- ions.

this theory sucks because it's very limited in its definition in that acid-base reactions can only occur in aqueous solutions when in fact, they can occur without the presence of water.

Then BRØNSTED-LOWRY came along and said...mmm let's make a better definition of things. let's define that acid is a proton donor and base is a proton acceptor. this is much better because now we dont need water!! for example if you have liquid ammonia NH3, is a base in the presence of water (a base becuase NH3 takes a proton from water so it becomes NH4 (more stable form of the compound) and water, now loses a proton, becomes OH-, a base). BUT if you throw NH3 into a basic solution , hey a base into a base is a basic solution right??? WRONG... NH3 actually donates a proton from itself and give it to the base, why does it do that? because the law of equlibrium says so and it involves transfer of electons and orbits which i am not get into the whole mocular structures, but NH3 into a NH2- and produces a proton, which is now acidic.

the bronsted-lowry theory also explains why a strong acid, like HCl, replaces a weaker acid, like HF, in a solution so when you do the math calculations you can forget about the H produced by HF cuz it's a weak acid.

this theory is also good for explaning why water can act both as a acid and a base. you put water in base it acts like acid, produces H3O+.

that's why if you get burned if you have HCl on your hands, because your skin contains water and the two reacts and produces acid that can do searious damage to your body. if your hands were completely dry then you wont get burned.

[james_bond_rulez]

writing this made me recall a scene from Fight Club

TYLER
Lye -- the crucial ingredient for making soap. A paste of lye and
water can burn through an aluminum pan. A solution of lye and water
will dissolve a wooden spoon. Combined with water, lye heats to over
two hundred degrees.

Tyler licks his lips until they're gleaming wet. He takes Jack's hand
and KISSES the back of it. The saliva shines in the shape of the kiss.
Tyler poises the can of lye over Jack's hand.


ok let's see the reaction : lye NaOH or KOH dissociates in water completely into K+ or Na+ and OH-, lots of OH- so BURNS

a little of vinegar, acetic acid (CH3CO2H), neutrilizes the burn cuz it dissociates into CH3CO2- and H+ (but in little amount), that was that vigegar is a weak acid.

yeah acids and bases rulez