The reaction above is a typical combustion reaction which are very common with hydrocarbons. Combustion occurs in the presence of oxygen to product carbon dioxide and water. The purpose of this reaction is to transform chemical energy into useful heat energy. Most times, the oxygen used is always in excess of the hydrocarbon reacting with it.
It is a common observation that a strip of aluminium metal in aqueous copper(II)Sulfate does not show any visible reaction. Aluminium is normally expected to displace copper in solution since it is higher than copper in the electrochemical series.
The reason for this is that aluminium forms an oxide film around its surface which prevents reaction with aqueous copper(II)Sulfate. This oxides film protects the aluminium surface such that it is now unable to react with the aqueous copper(II)Sulfate
The answer is (1) 10. The protons of Mg atom is 12. So the Mg atom has 12 electrons. The Mg2+ ion has lost two electrons so it has two positive charge. Then the answer is 10 electrons.
