Laboratio 5 Quimica

Colegio Bilingüe “Los Andes”
Química
Catedrática Hilda Palma de Martini

Classifying Chemicals Using Properties

Diego Centeno Alvarado
Undécimo Grado
Clave: 3
Guatemala, 13 de febrero de2012
Lab 5 – Classifying Chemicals Using Properties
Assignment
In the following lab you will examine samples of unknown substances. While you examine these substances you need to try and classifythem either as a mechanical mixture, a solution or a pure substance.
Make sure you read and then write out the lab before you begin. Remember to follow the safety precautions of working in the lab andhave all of your materials prepared before you start!
LAB 5: CLASSIFYING CHEMICALS WITH DATA (Write out the lab).
PROBLEM: How can you classify unknown materials as mechanical mixtures, solutions orpure substances?
HYPOTHESIS: How do you think it is going to turn out? Use the facts you already know to come up with a guess that might really make sense. Materials can be determined as mechanicalmixtures, solutions or pure substances by studying their shapes, appearances, and properties.
MATERIALS: 
-12 samples of unknown materials
-Data table about properties of pure substances (Seebelow).
TABLE: PROPERTIES OF SOME PURE SUBSTANCES
PURE SUBSTANCE | MELTING POINT (0C) | BOILING POINT (0C) | DENSITY (g/cm3) | APPEARANCE |
ethanol (alcohol) | -115 | 78 | 0.8 | clear colourlessliquid |
aluminum | 660 | Substance decomposes(break apart) rather than change state. | 2.7 | silvery-coloured solid |
sodium bicarbonate (baking soda) | Substance decomposes(break apart) rather thanchange state. | Substance decomposes(break apart) rather than change state. | 2.2 | white solid |
copper (II) sulphate (bluestone) | Substance decomposes(break apart) rather than change state. |Substance decomposes(break apart) rather than change state. | 2.3 | blue solid crystals |
carbon (diamond) | 3500 | 3930 | 3.5 | colourless solid crystals |

carbon (graphite) | 4000 | 3930 | 2.3 |...