Name each of the following according to its vertices.
point A
A
A.Reaction of iron with acids
1.Drop some iron filling into a test tube of dilute hydrochloric acid. Describe what happens.
I). When reaction stops, note the color of the solution.
ii). Have Fe3+ or Fe2+ formed
iii). Write an equation for this reaction.
2.Drop some iron fillings into a test tube of dilute nitric acid. Iron (II) nitrate formd at first but gets changed to iron (III) nitrate. What colour change occur. Is dilute nitric acid an oxidizing agent or a reducing agent? Explain. Write an equation to explain these results.
1. When iron filings are dropped into a test tube of dilute hydrochloric acid, they react to produce hydrogen gas and an iron chloride solution. This reaction can be represented by the equation:
Fe(s) + 2HCl(aq) → FeCl2(aq) + H2(g)
i) The color of the solution is pale green due to the formation of iron chloride.
ii) Fe2+ ions are formed in the solution.
iii) Equation: Fe(s) + 2HCl(aq) → FeCl2(aq) + H2(g)
2. When iron filings are dropped into a test tube of dilute nitric acid, initially iron (II) nitrate is formed, which then gets oxidized to form iron (III) nitrate. The color change that occurs is from pale green (iron (II) nitrate) to yellow/brown (iron (III) nitrate).
Dilute nitric acid acts as an oxidizing agent in this reaction. It oxidizes the Fe2+ ions to Fe3+ ions. Nitric acid itself gets reduced in the process.
The equation for the formation of iron (II) nitrate is:
3Fe(s) + 8HNO3(aq) → 3Fe(NO3)2(aq) + 2NO(g) + 4H2O(l)
The equation for the oxidation of iron (II) nitrate to iron (III) nitrate is:
2Fe(NO3)2(aq) + H2O2(aq) → 2Fe(NO3)3(aq) + 2H2O(l)
(Note: The oxidation of iron (II) nitrate can also be achieved by using atmospheric oxygen instead of hydrogen peroxide. In that case, the equation would be different.)