The Aim of the Experiment
This paper presents an experiment that was conducted to determine the activity of reaction of period three elements with Oxygen, Chlorine the reactions of the third row Chlorides and Oxides. The main aim of this experiment was to determine the optimum pH level.
Introduction
List of equipments and chemical used
The equipments used in the experiment were 6 tubes tests, several plastic pipettes, 6 Scoopula, Test Tube holder, Tissue and pH test paper. On the other hand, the chemicals used were five at: NaCl3, AlCl3, MgCl2, SiO2, and Water distilled. In the end the risk assessment table.
Risk assessment/Safety
- Use of lab coat, to avoid any damage in the cloths and use of the glass to protect the eyes, when use of the chemical.
- Turn the yellow flame ,when you not working to prevent accident or fire
- Handling the bottles substances by the top to avoid spilling its acidic chemical contents, can consequences in burn the skin and others material, to prevent handle the chemicals carefully.
- Report any accident to teacher or lab technician
- Keep bench clear and tidy, wipe up small splashes with a damp cloth or paper.
Methods
Experience
(Was performed by Carla, in the present of the tutor)
For reaction of the third row chlorides
- 1 tube – NaCl3+water distilled =water not clear (to much NaCl3) =PH 6 (green dark)
- 2 tube- MgCl2+water distilled= water clear (the crystal dissolved in the water) =PH 4(light orange)
- 3 tube-SiO2+ need to research resulted in the internet
- 4tube- PCl5+ water distilled= a small amount of gas, the water transform in light pink colour=PH1 (light pink)
- 5 tube –S2 Cl2+ need to research resulted in the internet
- 6 tube – AlCl3+ water distilled= reaction was gas =PH 4(light orange) inside in the water, the gas in the tube show PH 1(dark brown)
Experience
(All the next experience was performed by the tutor)
Reaction of third row element with oxygen
- 1- Mg= burn with very bright light and Mg transformed in white colour
- 2-Al=
- 3- Phosphorus red= melt of the element, reaction burn fast releasing a large amount of gas
- 4-Al (Aluminium) in powder fine=no reaction maybe because used to must powder (researched results in net)
- 5-Sulphurs powder (yellow powder) =burn with Oxygen given a electrical blue light in the beginning, and end with blue light releasing gas
- 6-Sodium metal (solid) = burn and flame given a red/orange colour, releasing a small amount of gas. Living ache at the end.
Experience
(All the next experience was performed by the tutor)
Reaction of the third row oxides.
*** Preparation of SO2
H2So4, Cu (piece of copper) and Cu (copper powder)
Mixed the piece of copper+copper powder in the tube, realising dropping of acid H2So4 by the funnel, and heating the tube, allowing the elements reacting and change colour (blue) and releasing a gas.
PH3 (orange colour)
Experience
(Research in the internet, not possible to perform this experience in class)
Reaction of the third element with chlorine
Reactions of the third row elements with oxygen.
Results and Discussions
Most period three elements readily react with oxygen when ignited using a Bunsen burner flame. However, the reactivity rates differ from one element to another across the period. For instance, sodium is the most reactive element with oxygen in period three. It burns vigorously with a golden yellow flame. This is due to the fact that the valent electron is loosely held and thus experiences a low electrostatic force making it easier to be kicked out from the outermost energy level (Beavon & Jarvis, 2000). Argon has a stable octet configuration and therefore it neither gains nor loose electrons. As a result, it does not react with oxygen.
Hence, the order of reactivity of period three elements beginning with the most reactive is Na>Mg>Al>Si>P>S>Cl>Ar (Beavon & Jarvis, 2000). This reactivity order indeed follows the ability of each individual element to lose oxygen. The table below summarizes the equations of reactions which takes place when period three elements are burnt in oxygen
Reactions of the third row elements with chlorine
Results and Discussions
Similar to the above experiment, most period three elements continue to burn when lowered into a gas jar of chlorine. However, the reactivity rates differ from one element to another across the period (Wulfsberg, 2000). Since sodium has the highest tendency to lose its valent electron owing to low electrostatic force, it reacts more readily with chlorine forming a white compound of sodium chloride. Moving across the period, the additional electron added to the outermost energy level increases electrostatic charge at the nucleus of the atom thereby making it more difficult for the atom to lose the valent electron (Beavon & Jarvis, 2000). Hence, the order of reactivity of period three elements starting eth the most reactive is Na>Mg>Al>Si>P>S>Cl>Ar. The table below summarizes the equations of reactions of these elements with chlorine.
The reactions of the third row oxides
Results and Discussions
As can be observed in the table above, dissolving metallic oxides on water yield basic solutions with the exception of aluminum oxide which has both acidic and basic properties (amphoteric). Across the period from sodium, the trend is such that the oxides move from being basic, amphoteric and then acidic. Hence, it is possible to generalize that metallic oxides such as sodium oxide and magnesium oxide which are also characterized with giant ionic structures and ionic bonding tend to be basic in nature while the molecular oxides of period three elements (covalently bonded) tend to be acidic(Wulfsberg, 2000).
Reactions of the third row chlorides
Results and discussions
Both sodium chloride and magnesium, chloride are purely ionic compounds. When they dissolve in water, they form hydrated ions (Beavon & Jarvis, 2000). The H3O+ ions generated by aluminium chloride in water are responsible for the acidity of aluminium chloride solution in water. Nonetheless, the trend in the pH of the period three chlorides formed in water shows that the pH lowers across the period: there is a gradual drop in pH of the chloride solutions from the metallic to non metallic oxides (Wulfsberg, 2000). This is due to the increasing tendency of the chlorides to hydrolyse which implies that the more they hydrolyse in water, the lower their pH values and hence increasing acidity. The table below summarises the reactions of period three chlorides with water.
References
Beavon, R. and Jarvis, A. (2000). “Structure, bonding and main group chemistry”, Cheltenham: Nelson Thomas Ltd.
Wulfsberg, G. (2000). “Inorganic chemistry”, CA: University Science Books.