Using English to Report

I.   Title       : Element identification

II.  Purpose  : Examines the similarity of the properties of elements in the periodic table

III. Theoretical basis

The flame becomes characteristic of the elements. The sharp yellow flame color is a practical way to determine the element of sodium. This is why flame testing can be used to determine unknown solutions. The halide and alkaline and alkaline earth salts may react with a more oxidizing halogen, thus forming a halogen of the halide. The order of oxidizing forces is F2> Cl2> Br2> I2. F2 can oxidize Cl- to Cl2 and Cl2 can oxidize Br- to Br2 and so on. While Br2 can not oxidize Cl- to Cl2. The reaction can be seen as follows:

Cl2 + Br- à Cl- + Br2

            Cl2 + I- à Cl- + I2

            Br2 + Cl- à does not react

In this reaction to obtain chlorine can be made chlorine water by heating a mixture of MnO2 with HCl 6 M. The heater used enough spirtus lights. The formed gas is flowed into distilled water. Reaction equation:

MnO2 + 4HCl à MnCl2 + 2H2O + CL2 (Epinur, et.2013: 25-26)

The alkaline earth metals, having 2 valence electrons whose oxidation rate is only 1 is +2. This element can also be known by examining the flame color of the salt changes (Ahmad Hiskia 1993: 119-126).

Elements in 1 group have many chemical properties. The chemical properties are determined by the valence electrons, the electrons in the outer shell of the passageway, since the valence electrons of elements belonging to one another are of the same chemical nature. IIA metal ion, the suit is reduced to free metal, because the potential price of the reduction is large and negative. The alkaline earth metal compounds as described above are alkaline earth cations having high positive charge density. When dependent on a particular anion, the cation will give high lattice energy and the salts may be slightly soluble or insoluble in water (Raip H Pertucci.1993: 51-53, 96-106).

IV. METHOD OF EXPERIMENT

4.1   Tools and Materials

A.    Tools :

6 reaction tubes

Ø Nichrome wire

Ø Flame bunsen

Ø Shelves

B. Material

Ø BaCl2 0.5 M solution

Ø CaCl2 0.5 M solution

Ø LiCl 0.5 M solution

4.2   Works Scheme

-   Each 2 ml of BaCl2 solution 0.5M, NaCl 0.5M, LiCl 0.5M, KCl 0.5M, CaCl2 0.5M, and SrCl 0.5M Inserted each into the test tube

-  Nikrom Wire  Heated on blue flame bunsen

-  Dipped on Barium solution

-  Cleaned wire into concentrated HCl solution (12M) & heat to red

-  Repeat flame test for Calcium, Lithium, Potassium, Sodium, and Strontium solution

V. RESULT 

NO	Substance	Colour	Information
1	CaCl2	Red	Alkaline earth
2	BaCl2	Yellow	Alkaline earth
3	SrCl2	Red	Alkaline earth
4	KCl	Purple	Alkaline
5	NaCl	Orange	Alkaline
6	LiCl	-	-

VI.  Discussion

         The elements of the alkaline and alkaline earth classes are highly reactive elements. The alkaline and alkaline earth elements also give different colors to the flame. Flame tests are usually used to identify alkaline and alkaline earth elements. Electrons in atoms can move from one skin to another. When electrons move from lower skin there will be release of energy in the form of electromagnetic radiation with a certain wavelength. If the radiation is in visible light, it will be visible color.
VII. APPENDIX