Aluminum Hydrochloric Acid Reaction
We must have seen electric wires in between utility poles on road sides, silver utensils and coloured aluminium sheet for making roof. What the common thing in all of these is?
They all are solid in form and metal. What do you think about diamond and sulphur powder?
Both are nonmetals and can easily identify from metals.
Metals have luster surface which can observe on copper and aluminum utensils. They are hard, malleable, ductile and good conductors of heat and electricity.
The metallic lustre is caused by free electrons as they can reflect light.
That is the reason; they are used as electric wires.
The free electrons in metallic lattice are responsible for conductivity of metals.
Due to metallic bond between free electrons and metal cation, metals show malleability and ductility.
The disadvantage of these free electrons is corrosive nature if metal, which is due to oxygen gas in the atmosphere, creates an imbalance of electrons and positive ions in the metal and rust is produced.
But we cannot draw wires of phosphorus and sulphur as they are non-metals and cannot drawn as wires.
They are brittle and easily break also.
Non-metals have less density and low melting and boiling points. On the contrary; metals are heavy with high density and high melting and boiling points. In periodic table out of all elements more than 75% elements are metal in nature and positioned at left side of table.
All metal show electropositive nature as they can loss their valence shell electron to become stable.
Therefore when a metal atom loses electrons it becomes metal cation.
Let’s discuss some of the chemical properties of metals with different reagents. Metals can react with atmospheric oxygen and form metallic oxides. As the reactivity of metal increases, they can easily convert into metallic oxides.
For example; sodium is highly reactive and quickly reacts with atmospheric air to form sodium oxide.
Metallic oxides are alkaline in nature and forms ions in their aqueous solution such as sodium oxide reacts with water to form sodium hydroxide. Reaction of metal with acid depends on reactivity of metal atoms.
Highly reactive metal can reacts with dilute acids with release of hydrogen gas while a less reactive metal reacts with strong acid under drastic conditions only. We can check the reactivity of metals in the reactivity series of them.
According to this series; Lithium metal is most reactive and place at the top of series while noble metals such as Gold, Platinum are least reactive and place at the bottom of series.
The reaction of metals with inorganic acids such as hydrochloric acids results the formation of metallic halide and hydrogen gas.
The reaction of sodium with HCl forms sodium chloride and hydrogen gas. The reaction can be written as given below;
2Na + 2HCl → 2NaCl + H2
But Copper and Silver cannot react with dilute HCl due to less reactivity.
Aluminium metal can easily dissolve in dilute sulphuric acid or dilute hydrochloric acid. It forms soluble aluminium sulphate and release H2 gas with H2SO4 acid.
Similarly with HCl, it forms AlCl3 (aluminium chloride) and H2 gas.
Both reactions can be written as given below;
2Al(s) + 3H2SO4(aq) → 2Al3+(aq) + 2SO42-(aq) + 3H2(g)
- 2Al(s) + 6HCl(aq) → 2Al3+(aq) + 6Cl-(aq) + 3H2(g)
The reaction occurs violently and hydrogen gas comes out with whisper sound with the liberation of some heat.