Answer: Single replacement
Explanation: A single replacement reaction is one in which a more reactive element displaces a less reactive element from its salt solution.
When iron is treated with a strong acid such as [tex]HCl[/tex], iron being more reactive than hydrogen displaces hydrogen from its salt solution and thus produce ferric chloride and hydrogen gas.
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.
[tex]2Fe+6HCl\rightarrow 2FeCl_3+3H_2[/tex]
