group five

Making Ionic Compounds

In chemistry, an ionic compound is a chemical compound in which ions are held together in a lattice structure by ionic bonds. Usually, the positively charged portion consists of metal cations and the negatively charged portion is an anion or polyatomic ion. Ions in ionic compounds are held together by the electrostatic force between oppositely charged bodies. Ionic compounds have a high melting and boiling point, and they are hard and very brittle.

Positive and negative ions are attracted to each other to make ionic compounds.  They easily form crystals. They tend to have high boiling and melting points. They conduct electricity when they dissolve in water.

Ions can be single atoms, as the sodium and chloride in common table salt sodium chloride, or more complex groups such as the carbonate in calcium carbonate. But to be considered an ion, they must carry a positive or negative charge. Thus, in an ionic bond, one 'bonder' must have a positive charge and the other a negative one. By sticking to each other, they resolve, or partially resolve, their separate charge imbalances. Positive to positive and negative to negative ionic bonds do not occur. (For an easily visible analogy, experiment with a pair of bar magnets.)

Ionic compounds are usually formed when metal cations bond with nonmetal anions. The only common exception I know to this is when ammonium is the cation - there's no metal in ammonium, but it forms ionic compounds anyhow.

Formation of Ionic Compounds

 This is a tutorial on writing ionic compounds (by MarkResengarten on YouTube) 

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

http://www.nelsonthornes.com/secondary/science/scinet/scinet/elements/compound/ionic.htm

Colored Reactions

Whenever a chemical reaction occurs, the changes that people observe are caused by the creation or loss of certain types of materials. For instance, temperature can generate a chemical reaction. An easy way to recognize a chemical change is to compare the color of the original item with the new one. A number of chemical reactions cause color changes.

In chemistry, a colour reaction is a chemical reaction that is used to transform colourless chemical compounds into coloured derivatives which can be detected visually or with the aid of a colourimeter.

The concentration of a colourless solution cannot normally be determined with a colourimeter. The addition of a colour reagent leads to a colour reaction and the absorbance of the coloured product can then be measured with a colourimeter.

Colourimeter

A change in absorbance in the ultraviolet range cannot be detected by eye but can be measured by a suitably-equipped colourimeter. A special colourimeter is required because standard colourimeters cannot operate below a wavelength of 400 nanometes. It is also necessary to use fused quartz cuvettes because glass is opaque to ultraviolet.

Many different colour reagents have been developed for determining the concentrations of different substances. For example, Nessler's reagent can be used used to determine the concentration of a solution of ammonia.

 

Chemistry experiment - KMnO4 + NaOH + sugar (by TomIRIDIUM on YouTube)

 purple (MnO4- ions) // blue (MnO4 3- ions) // green (MnO4 2- ions) // orange (Mn 3+ ions) 

The secret of this color change is pH. Chemicals with a low pH (0-6) are acidic, while those with a high pH (8-14) are basic. (A pH of 7 is neutral: neither acidic nor basic.) Universal indicator is a chemical that changes color in the presence of acids and bases from a pH of 2 to 10. Acids turn the indicator red, pink, orange, and yellow, while bases turn it green, blue, and purple. Vinegar is an acid, so when you poured the indicator solution into the second flask, it turned red. Ammonia is a base, so when you mixed the acidic vinegar solution with ammonia, it raised the pH and the water turned blue. If you had enough vinegar in your last flask, the solution should have turned red again.

Chemistry Magic : Confounding Color (by homesciencetools.com)
A video on Color Reaction

Chemical Reactions That Cause Color Change | eHow.com http://www.ehow.com/list_7501675_chemical-reactions-cause-color-change.html#ixzz19xFnYmzx

http://en.wikipedia.org/wiki/Color_reaction
http://www.hometrainingtools.com/color-change-chemistry-newsletter/a/1549/ 
http://www.hometrainingtools.com/color-change-magic-trick-project/a/1550/ 

group five

Rodriguez

Rosadia

Sevalla

Solis

Tan-Palanca

Trinidad