Second Lab Session - Elements' properties

Maite Pérez and Javier Mondaza

23/01/2013

Objective: To investigate the main properties of elements.

Background:

In the same way books are arranged in alphabetical order, by publishing companies, etc, in libraries to found them easier; in the chemistry laboratory we arrange elements in bottles, indentified by a label which indicate us many things.

Today, we are also going to focus on those ones which don't appear on the labels, such as: melting and boiling point, electric continuity, etc.

In order to calculate electric continuity, we will use a hand-made electrical continuity measurer:

It will help us in order to obtain a close loop electrical circuit capable of conducting current, so we can measure with it its electrical continuity. (See the image in the materials' list). 

Materials:

     

              -3 test tubes                                - Test tube holder      - Hand-made electrical continuity measurer

                  

         - Propanol                                  - Sodium acetate                                                    - Lead

                               

        -Thermometer                                                        - Ceramic plate

In today's lesson, we have been calculating the boiling point of Propanol. 

  

Videos on the following post due to technical problems

Then,  by using the we measured its electrical continuity, by using a hand-made electrical continuity measurer (see in Materials) .
 It is measured by touching with both poles of the device with the element or compound we are testing. If the bulb turns on, it means that the substance is a conductor; if not, it is an insulator.

Finally, we made up a table which recollected all the data we had obtained and investigated.

Name	Element/ Compound	Chemical Representation	Smell	Colour	Shine	Aggregation State
Propanol	Compound	CH3 CH2 CH2 OH	Yes- Strong	Colourless	-	Liquid
Sodium Acetate	Compound	CH3 COO Na	Yes- mild	White	No	Solid
Lead	Element	Pb	Yes - mild	Grey	No	Solid

Melting point	Boiling point	Magnetism	Combustibility	Solubility in water	Solubility in organic solvent	Reactivity vs H2O
-126°C	86°C	No	Yes	Yes	Yes	No
58 °C	337°C	No	No	Yes	No	No
327.5 °C	1470 °C	No	No	No	No	No

Reactivity vs base	Reactivity vs acid	Ph aqueous solution	Electricity
No	No	Neutral	No
No	No	Neutral	No
No	No	-	Yes

Because of the extremely high boiling points and low melting points, we could not reach them in the lab, and that is why we looked for information on the Internet (RUBIN, 2011)

Conclusions

In today's class we have only been participating Javier and Maite. We have been working in group, always helping each other in order to go faster. While one was recording, the other was heating up the propanol, and then we swapped.

At the beginning, we were both a bit scared because, as we know, propanol is a very flammable substance,  which can explode very easily. Because of this, we took our time to heat up the propanol. We have also been very careful, in order to avoid  propanol pouring from the test tube.


Bibliography

RUBIN, Julian (2011): Boiling and melting points of elements. Taken from:

http://www.chemistry.patent-invent.com/chemistry/melting_boiling_point.html