OK this is my first blog post. I plan on posting a variety of entries on how to synthesize various compounds that have interesting chemical properties or have uses in pyrotechnics. However to carry out these procedures it is necessary to have a basic knowledge of chemistry and lab safety. Most I'm sure have forgotten their high schools chemistry courses unless they are currently enrolled so this will be a basic review of most of the information need to preform these yourself or make your own compounds.

I will start with the elements. A periodic able is the best way to show all the elements.

http://www.wisegorilla.com/images/chemstry/0-Periodic%20table.gif

A group is a vertical column in the periodic table of the elements and a period is a horizontal row. Elements in the same group tend to have similar properties.

The atomic number (also known as the proton number) is found above the abbreviation of the elements name. It is the number of protons found in the nucleus of an atom. The atomic number uniquely identifies a chemical element. In an atom of neutral charge, atomic number is equal to the number of electrons.

The atomic mass is found below the elements abbreviation indicates the weight in grams of 6.022×10²³ atoms of the substance (one mole). It is vital to have a periodic table with atomic masses to accurately calculate equations.

Anions and cations are a very important concept to understand in inorganic chemistry. Ionic compounds are charged groups inorganic compounds comprised of a cation (positively charged group) and an anion (negatively charged group).

http://www.jesuitnola.org/upload/clark/Refs/tableions.GIF

The list on the left shows cations and their charges and the right shows anions and their charges. This is useful to determine the formula of ionic compounds. Group one always has a charge of 1+ so sodium, potassium, lithium etc and group two all have a charge of 2+ so calcium, magnesium etc are not included in this list as they are easily predicted. If you want to find the formula of sodium sulfate first find the charge of sodium (always 1+) then sulfate (2-) if they are simply combined we get Na¹⁺SO₄^2- but all ionic compounds have neutral charges and the net charge of this is 1- (found by adding 1+ and 2-) so the equation is balanced to Na₂SO₄ this gives a net charge of zero telling us this is the compounds formula!

Also say you want to find the formula of calcium hydroxide find calcium's charge (2+) then hydroxides charge (1-) the compound CaOH has a charge of 1+ so this isn't the formula. We need twice the number of hydroxides so you might be tempted to change it to CaO₂H₂ or CaOH₂ however the anion needs to stay "intact" so the fomula changes to Ca(OH)₂ which has a net charge of zero meaning it is the formula for calcium hydroxide.

Some cations can have several charges such as copper. For this the stock system is used. Copper (l) indicates the copper has a charge of 1+ copper (ll) indicates a charge of 2+ and copper (lll) indicates a charge of 3+ knowing these charges allows you to find the chemical formula from the name.

Knowing what will react is another important skill. For this we use the activity series of metals.

http://grandinetti.org/Teaching/Chem121/Lectures/SolutionReactions/assets/ActivitySeries.png

At the top are the most reactive and the bottom are the least reactive. Say we want copper metal from copper sulfate. We would make a solution of copper sulfate then add a more reactive metal than copper the addition of iron, zinc or magnesium would all precipitate copper however the addition of silver mercury or platinum metal would have no effect. a good way to think of it is that the higher metals are stronger. Copper is weak because it is low down if it is bonded to the sulfate and metallic iron comes along the iron steals the sulfate because it is "stronger" or more reactive leaving the copper metal without a sulfate.

Balancing chemical equations is also required to do chemistry.

Say we want water from hydrogen and oxygen we write the equation H₂+O₂=H₂O however there are two oxygens on the left and only one on the right so we re write the equation 2H₂+O₂=2H₂O the 2 in front of the H₂ and H₂O indicate two atoms or two moles of each substance (NOT TWO GRAMS!) are required for this reaction (it is important to understand that two grams of hydrogen and one gram of oxygen doesn't make two grams water).

Once we have a chemical equation we can use the periodic table to transform atoms to grams. For example 2Na+Cl₂=2NaCl this is the balanced equation for making salt from sodium and chlorine. There are two sodium atoms so the atomic mass of sodium is found (22.9) and multiplied by two (45.8) there are two chlorines together (because chlorine is diatomic) so the atomic mass of chlorine is found (35.4) and it is multiplied by two (70.8) therefore we know 45.8g sodium metal and 35.4g chlorine will combine to form 116.6g sodium chloride.

Solublity is another concept of chemistry. Many ionic compounds dissolve or dissociate in water

http://intro.chem.okstate.edu/1314F00/Lecture/Chapter4/SolTab.gif

This table lists soluble and insoluble ionic compounds. when as compound dissolves in water the ionic bond is broken and the compound is ripped apart into its anion and cation. This can be shown like so NaCl=Na⁺+Cl^-.

We can find what will precipitate in a reaction using this table. For example NaCl+AgNO₃=AgCl+NaNO₃ in this double replacement reaction sodium chloride and silver nitrate combine to form silver chloride and sodium nitrate. Looking at the reactants we know all nitrates are soluble so we know the silver nitrate dissolves in water also all sodium salts are soluble so we know the sodium chloride dissolves. In the products we note all chlorides are soluble EXCEPT Ag, Pb and Hg₂ so we know silver chloride is insoluble and therefore will precipitate. All sodium salts are soluble so we know the sodium nitrate will remain in solution.

As far as lab safety goes wear gloves and a respirator when needed, never do experiments in the house, add acid to water and research before doing any reactions.

I could go into thermodynamics, enthalpy, limiting reagents etc. but I don't think it is necessary. Thanks for reading I plan to have some experiments up soon!