Corrosion

Corrosion 1

Aim: To investigate the factors that cause rusting in iron.

Equipment: Four test tubes, test tube rack, a bung, four iron nails, boiled water, tap water, salty water, cooking oil, calcium chloride.

Method: 

1. Label four test tubes A - D and place in a test tube rack.

2. Test tube contents: A = Iron nail and tap water 

                                  B = Iron nail and salty water

                                  C = Iron nail, boiled water, oil.

                                  D = Iron nail and calcium chloride. Sealed with a bung.

3. Leave the test tubes undisturbed for at least three days. 

Corrosion 2

(prevent rusting)

Aim: To investigate a number of techniques that may prevent rusting.

Equipment: Four test tubes, test tube rack, a bung, four iron nails, tap water, Vaseline gel, nail polish or paint, zinc pellets or magnesium ribbon.

Method: 1. Label four test tubes A - D and place in a test tube rack.

2. Fill all test tubes with equal volumes of water - enough to cover the nails.

3. Test tube contents: A = Iron nail

                                  B = Iron nail covered in Vaseline

                                  C = Iron nail painted with nail polish or paint

                                  D = Iron nail with a small piece of magnesium ribbon wrapped around it, or with zinc pellets added to the test tube. 

4. Leave the test tubes undisturbed for at least 3 days.

Conclusion: As you can see in the photo above the experiment worked successfully!

Science - Making salts

Making Salts 

Aim -  To produce sodium chloride salt by carrying out a neutralisation reaction.

Equipment - 50 mL and 200 mL bealers, dilute HCI (hydrochloric acid), dilute NaOH (sodium hydroxide), 25 mL measuring cylinder, a glass stirring rod, spotting tile, universal indicator solution, tripod, gauze mat, bunsen burner, evaporating basin. 

Method - 

1. Using the measuring cylinder measure 10 mL of HCI and pour it into your 50 mL beaker. Add dilute NaOH a few drops at a time while stirring with the glass rod. 

2. Every 10-15 drops stop adding the NaOH and use the glass stirring rod to transfer a drop of the solution to a spotting tile. Test its pH using universal indicator.

3. Keep adding NaOH and testing the solution by repeating step 2. Ad you get closer to neutral you may need to test the solutoin after every drop. 

4. Pour the neutral solution into an evaporating basin and evaporate the water out of the solution using the equipment set up shown above.