An unknown solution is found to have the ability to conduct an electrical current. When iron metal is exposed to the solution, it reacts and produces an orange precipitate and hydrogen gas. This unknown solution is best characterized as what?

1 Answer
Jul 1, 2016

Can be any acid for example either HCl or HBr or #H_2SO_4# or some other one.


You might have learnt about reaction of metals ( metal oxides, metal carbonates, metal oxides or metal hydroxides, only metal ) with acids.

After analyizing that only #color(green)"METAL + ACID"# produces #color(green)"HYDROGEN"#.

We get to know that it was an acid, that conducts electricity as it is a solution ( aqueous ) that has mobile ions and free electrons.

Now, our both conditions for an acid are fulfilled;

  • Conduction of electricity
  • Production of Hydrogen gas

So the solution can be any (strong) acid i.e either #HCl# or # H_2SO_4# or some other acid .

THE EQUATION WE GET; {unbalanced equation}

#Fe_(s) + HCl_(aq) => (FeCl_3)_(aq) + H_2(g)#

so, we can say that (brownish) orange
solution formed was #FeCl_3# as #Fe^3+# has orange colour.

So it can be any acid.