miércoles, 15 de octubre de 2014

Lab Report 1

Blog tasks
The whole report must be posted to your group blog. Make sure you include:
1.    A table of results.
2.    The type of bonding present in each substance.
3.    A secondary table to show “expected” results. (Research the type of bonding and the expected results for the test that you carried out)
4.    A conclusion comparing the actual results with the expected results.
5.    An evaluation that suggest improvements that could be made to your method.

6.    A minimum of 2 references (APA format).

Obtained results & Expected results for our components:




For Iron (III) Sulphate , this compound is formed by an ionic bonding, this means that the sulphate steals the electrons that iron wants to lose. By this I mean that Iron, which is a metal and has a flow of electrons which maintains the atoms in place (Magnetic field), sulphate, which is a negative ion, (electronegativity) wants to get, and pulls to it those iron electrons. This will give the compound the characteristics of an ionic compound, and, this means that this material will probably melt at a really high temperature, it will form maybe crystals, could maybe dissolve in water, (water is polar), this means the negative parts from the compounds will go with positive parts from water and, negative parts from water with positive parts of the compound. This compound could maybe conduct electricity, but, there are loads of ionic compound with exceptions, whith some characteristics from this ionic compound but not all, of those which are expected.




For Paraffin CnH2n+2, This compound is formed from methane, made up of atoms of hydrogen and carbon, which make a covalent bond, a organic covalent bond. This will give the compound some of the characteristics of covalent bonding, but it is an exception in the melting point, parafine molecules are really small, this causes its low melting point (70 degrees), with other covalent compounds such as diamonds which really large covalent molecules, it melting point is much higher. This compound will not dissolve in water because water is polar, and covalent bonding is neutral, I mean, don´t want to gain, or loose electrons, by the way it won’t conduct electricity, because their outer shells are with the perfect electron charge, and molecules won´t have a negative or positive parts, they have their charges balanced equally (Neutral), not electronegative.
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For starch, formed from glucose ( C6H12O6) join toguether by covalent bonds, called glucosydic bonds, is formed from carbohydrates hydrogen and oxigen. Giant Covalent moleculeThis is an organic compund, this means that we cannot melt it, because, it has energy, this means that if we put starch at high temperatures it will just burn the energy it has (combustion). It is not soluble in water because of the sizes of the molecules, its a powder so, you can remove and make all the particles movein water, but waiting like 2 minutes the powder goes to the bottom, as I said starch molecules have really big sizes and this makes water molecules cannot surround them.  It won’t conduct electricity, because their outer shells are with the perfect electron charge, and molecules won´t have a negative or positive parts, they have their charges balanced equally (Neutral), not electronegative..


For iron nails, formed from iron, have metal characteristics, very strong bonding between its atoms, this bond is really hard, making it, insoluble, with high melting point, and conduct electricity, the metallic bond is basically the atoms, and a sea of
electrons, this sea keeps all in order, and for breaking this bond it is nessesary loads of energy, energy that water, or low tempertures dont have. Metals conduct electricity because of the sea of electrons constandly moving around.

Conclusion

The results that we have obtained from the experiment, we have compared it into the result that we should have obtained and it shows that:
·         The expected results are nearly the same as the results of our experiment so that means that we have carried successfully the experiment.  
Also it shows us that the results are not very specific so we can´t really say that the expected results are nearly the same as our results because we had not measure correctly the melting point of the substance and the results are not very especific. In the melting point we tried to see if the melting point of different substances to see if they have a low melting point and if we see that the substance was not melting correctly we supossed that it have a high melting point.

Evaluation
Some improvements that can be made to the method could be:
·         The method says that only with one attempt we can carry the experiment, but if we carry more times the experiment, we will have more results to compare them and see if there was an abnormality in the experiment.
 The method also shows that for calculate the melting point we have to heat up the test tube with a bouncer burnerbut it doesn´t show how to heat it, if gentenly or more arresively or heat it in the botton or in the middle or in which part.
Another improvements that can be made in the method are the quantity of the substance that is used in the experiment, because it could be that if one substance have more quantities the properties could change like if we have 1L and 10L of water, the 10L of water take more time to boil even if the two substances are heat up at the same temperature because you need more energy to boil because there is more substance.
Also to measure the melting point, we didn´t use any measuring table, mechanism or tool and we like "invented the result" by looking how more time does it take to burn or how quickly, the best idea to make an improvements is to be measured with the correct tools and with a renew method.


  • CHEMWIKI.UCDAVIS.EDU

    Covalent Bonds - Chemwiki

    In-text: (Chemwiki.ucdavis.edu, 2014)
    Bibliography: Chemwiki.ucdavis.edu, (2014). Covalent Bonds - Chemwiki. [online] Available at: http://chemwiki.ucdavis.edu/Theoretical_Chemistry/Chemical_Bonding/General_Principles/Covalent_Bonds [Accessed 17 Oct. 2014].
  • Website

    HYPERPHYSICS.PHY-ASTR.GSU.EDU

    Sugars

    In-text: (Hyperphysics.phy-astr.gsu.edu, 2014)
    Bibliography: Hyperphysics.phy-astr.gsu.edu, (2014). Sugars. [online] Available at: http://hyperphysics.phy-astr.gsu.edu/hbase/organic/sugar.html [Accessed 17 Oct. 2014].



The properties of substances and their bonding


Assessed criteria: Criterion C - Processing and Evaluating


 

Level descriptor

7-8

The student is able to:
i. correctly collect, organize, transform and present data in numerical and/ or visual forms
ii. accurately interpret data and explain results using correct scientific reasoning
iii. evaluate the validity of a hypothesis based on the outcome of a scientific investigation
iv. evaluate the validity of the method based on the outcome of a scientific investigation
v. explain improvements or extensions to the method that would benefit the scientific investigation.

 

 

Objective
To study, evaluate and compare the properties of several substances and relate them to their type of bonding (ionic, covalent or metallic).

Theoretical background
The properties of substances are related to the kind of bonding present in those substances. The type of bonding depends on the atoms present and is related to their position in the periodic table.

Materials
Substances A to D                             Conductivity meter
Test tubes                                          Distilled water
Spatula                                                           Acetone
Bunsen burner

Method
Repeat the procedure for each of the substances provided:
1.    Take ½ a spatula of the substance in a test tube. Describe the appearance of the substance.
2.    Gently heat it in the flame of the Bunsen burner and state if the approximate melting point. (Low, intermediate or high).
3.    Take ½ a spatula of the substance in another test tube.
4.    Add 10 mL water, stir it and state whether the substance is soluble in water or not.
5.    Repeat the steps 4 and 5 using acetone instead of water.
6.    Using the conductivity meter, state if the substance is a conductor in solid state.
7.    If it the substance is soluble in water, test whether the solution is a conductor or not.

Blog tasks
The whole report must be posted to your group blog. Make sure you include:
1.    A table of results.
2.    The type of bonding present in each substance.
3.    A secondary table to show “expected” results. (Research the type of bonding and the expected results for the test that you carried out)
4.    A conclusion comparing the actual results with the expected results.
5.    An evaluation that suggest improvements that could be made to your method.

6.    A minimum of 2 references (APA format).