IB 2 Lab Report 14 – Product of Rusting

Design

Aim: The purpose of this experiment is to detect the metal oxidation that will lead to rust by using a ferroxyl indicator solution in the presence of Fe2+ ions.

Hypothesis: The reaction would most probably occur in an acidic solution and it would be more pronounced on the nails where the surface area is greater and the metal is weaker.

General Background:

The rusting of iron is primarily due to attack by hydrogen ions.

“In order that rust should be formed iron must go into solution and hydrogen must be given off in the presence of oxygen or certain oxidizing agents. This presumes electrolytic action, as every iron ion that appears at a certain spot demands the disappearance of a hydrogen ion at another, with a consequent formation of gaseous hydrogen. The gaseous hydrogen is rarely visible in the process of rusting, owing to the rather high solubility and great diffusive power of this element. Substances which increase the concentration of hydrogen ions, such as acids and acid salts, stimulate corrosion, while substances which increase the concentration of hydroxyl ions inhibit it.”

Hence, in order for the experiment to be conducted, an acidic solution would be required. This would be done by using the oxidizing agent – potassium ferricyanide (K3Fe(CN)6).


Control variables:

  • Concentration and volume of NaCl used
  • Concentration and volume of K3Fe(CN)6 used
  • Volume of phenolphthalein used


Independent variables
:

  • Iron (II) Sulphate FeSO4 crystal
  • NaOH solution
  • Iron nails – one bent and one straight

Dependent variables:

Join now!
  • Colour changes in the various reaction
  • Amount of rusting on the different nails

Materials:

Apparatus

  1. 1 × measuring cylinder (50cm3)
  2. 2 × dropper
  3. 1 × beaker (50cm3)
  4. 2 × test tubes
  5. Paper napkin

Reagents

  1. 15cm3 of 3% NaCl solution
  2. 10% of K3Fe(CN)6 solution
  3. Phenolphthalein indicator
  4. FeSO4 crystal
  5. NaOH solution
  6. 2 × iron nails


Method:

  1. First, 15cm3 of 3% NaCl solution, 4 drops of 10% K3Fe(CN)6 solution and 2 drops of phenolphthalein indicator were combined in a small beaker and ...

This is a preview of the whole essay