Explore Related Concepts

Best Results From Wikipedia Yahoo Answers Youtube

From Wikipedia

Chemical decomposition

Chemical decomposition, analysis or breakdown is the separation of a chemical compound into elements or simpler compounds. It is sometimes defined as the exact opposite of a chemical synthesis. Chemical decomposition is often an undesired chemical reaction. The stability that a chemical compound ordinarily has is eventually limited when exposed to extreme environmental conditions like heat, radiation, humidity or the acidity of a solvent. The details of decomposition processes are generally not well defined, as a molecule may break up into a host of smaller fragments. Chemical decomposition is exploited in several analytical techniques, notably mass spectrometry, traditional gravimetric analysis, and thermogravimetric analysis.

A broader definition of the term decomposition also includes the breakdown of one phase into two or more phases.

There are broadly three types of decomposition reactions: thermal, electrolytic and catalytic.

Reaction formula

The generalized reaction for chemical decomposition is:

AB → A + B

with a specific example being the electrolysis of water to gaseous hydrogen and oxygen:

2H2O(I) → 2H2 + O2

Additional examples

An example of spontaneous decomposition is that of hydrogen peroxide, which will slowly decompose into water and oxygen:

2H2O2→ 2H2O + O2

Carbonates will decompose when heated, a notable exception being that of carbonic acid, H2CO3. Carbonic acid, the "fizz" in sodas, pop cans and other carbonated beverages, will decompose over time (spontaneously) into carbon dioxide and water

H2CO3→ H2O + CO2

Other carbonates will decompose when heated producing the corresponding metaloxide and carbon dioxide. In the following equation M represents a metal:

MCO3→ MO + CO2

A specific example of this involving calcium carbonate:

CaCO3→ CaO + CO2

Metal chlorates also decompose when heated. A metal chloride and oxygen gas are the products.

2MClO3→ 2MCl + 3O2

A common decomposition of a chlorate to evolve oxygen utilizes potassium chlorate as follows:

2KClO3→ 2KCl + 3O2

Many metal carbonates decompose to form metal oxides and carbon dioxide when heated.

Sodium chloride - Wikipedia, the free encyclopedia

1 Properties; 2 Production; 3 Uses ....NaCl does not release heat upon ...

From Yahoo Answers

Question:Benzene diazonium chloride, C6H5NNCl, decomposes by first order rate law. If the rate constant at 20 C is 4.3*10-5/s, how long will it take for 61% of the compaound to decompose? I saw someone already asked a similar question but the solution was hard to follow. Please help!

Answers:The integrated first order equation is: ln[C6H5NNCl] = ln[C6H5NNCl]o - kt. The left side of the equation is the concentration of the reactant at any time t, so if 61% of the C6H5NNCl decomposes, then 39% remains. The concentration on the right side of the equation is at time t = 0; so we can let [C6H5NNCl]o = 100 and [C6H5NNCl] = 39. Just substitute; ln(39) = ln(100) - (4.3*10-5/s) t; Solving, t = 21,899 s; or about 6 hr 5 min.

Question:a) A sample of calcium carbonate is heated. b) Sulfur Dioxide gas is bubbled through water. c) Solid potassium oxide is added to a container of carbon dioxide gas. d) liquid hydrogen peroxide is warmed. e) Solid lithium oxide is added to water. f) molten aluminum chloride is electrolyzed. g) A pea sized piece of sodium is added to a container of iodine vapor. h) A sample of carbonic acid is heated. i) A sample of potassium chlorate is heated. j) Solid magnesium oxide is added to sulfur trioxide gas.

Answers:a) CaCO3 ~~> CaO + CO2 (Decomposition reactions usually produce simple salts and oxide gasses) b) SO2 + H2O ~~> H2SO3 (A nonmetal oxide in water will produce an acid) c) K2O + CO2 ~~> K2CO3 (CO2 + O ~~> CO3(2-)) d) 2 H2O2 ~~> 2 H2O + O2 (Decomposition reaction) e) Li2O + H2O ~~> 2(Li+) + 2(OH-) (A metal oxide in water will produce a base) f) 2 AlCl3 ~~> 2 Al(3+) + 3 Cl2 + 3e- (3 electrons are taken away from Al giving it its 3+ charge. The 3 electrons are given to the 3 Cl(1-) which converts them into a more stable form Cl2 gas. Al was oxidized and Cl was reduced.) g) 2Na + I2 ~~> 2 NaI (Na is oxidized and I is reduced) h) H2CO3 ~~> CO2 + H2O (Carbonic acid always decomposes into water and carbon dioxide) i) 2 KClO3 ~~> 2 KCl + 3 O2 (Decomposition reactions) j) MgO + SO3 ~~> MgSO4 (SO3 + O ~~> SO4(2-))

Question:I know the chemical formula is NaCl. Give a brief description of the types of bonds found in the molecule. What are some unique features of this molecule based on its chemical makeup? How does oxygen relate to this molecule? How do hydroxyl groups relate to this molecule? Answer as many as you can. Thanks!

Answers:sry all i know is that it is an ionic bond between a metal and a non-metal.

Question:(sorry for my bad english) how about getting potassium from banana?? one question again, can potassium chloride be subtituted by sodium chloride for general purpose (i want to get chlorate from potassium chloride. and i want to substitute potassium chloride with sodium chloride)???

Answers:Can we make KCl from NaCl? The answer: not easily. And not purely. Na and K have very similar chemistry and it would be very unusual to be able to separate Na+ from K+. The solubilities of KCl and NaCl are different enough that it might be possible to separate them by successive crystallization. But it be hardly worth the effort. For lots of reactions, they are interchangeable and only provide a source of chloride ion. Then you'll get sodium chlorate instead of potassium chlorate. This is interesting: "... potassium chlorate is produced by the electrolysis of a sodium chloride solution to form sodium chlorate, which is reacted with potassium chloride to precipitate potassium chlorate. The resultant sodium chloride is returned..." http://en.wikipedia.org/wiki/Potassium_chlorate The solubility of KClO3 is 7.19 g/100 ml (20C), while the solubility of NaClO3 is 101.0 g/100 ml (20C). Therefore, the KClO3 can be selectively crystallized and recovered.

From Youtube

Thermal Decomposition of Sodium Nitrate :Nuffield A level Chemistry Practical Thermal Decomposition of Sodium Nitrate

Electrolysis sodium chloride to Sodium hypochlorite :Improvised Electrolysis of sodium chloride to sodium gypochlorite (when higher temp, there can be sodium chlorate). Better image of electrolyser there - img262.imageshack.us