Does Rust Affect Metal’s Strength? Carolyn Riegel Grade Nine
Problem What solution will cause the most rust, thus resulting in the weakest metal?
Research Rust, or oxidation, occurs when certain metals are exposed to oxygen and water The water that hits the surface of the metal will form with carbon dioxide to become acid The rest of the water will separate into its two elements, hyrdogen and oxygen. Oxygen will combine with the acid to create iron oxide When regular water is the catalyst in the oxidation process it forms an acidic solution. If salt is used, no solution is needed because it is already a catalyst. Bleach is a potent oxidizer and readily accepts electrons from the iron
Hypothesis If steel wool is soaked in three different solutions, the salt solution will cause the steel wool to require the least amount force to rip apart.
Materials 9 beakers 9 pieces of steel wool ( about 5 cm² each) Distilled water ( 100 milliliters in three beakers) 10% salt concentration with distilled water in three beakers 10% bleach concentration with distilled water in three beakers Force Logger Pro Software Computer
Procedure Each steel wool piece was cut Beakers were filled with different solutions After 3 days, steel wool was removed from beakers and allowed them to dry off Force Logger Pro was used to test the force needed to rip the steel wool Independent variable: solution steel wool is placed in Dependent Variable: durability of the steel wool Constants: type of steel wool, time steel wool was in solution, temperature of room Control: steel wool placed in distilled water solution, steel wool not placed in any solution
Conclusion hypothesis : If steel wool is soaked in three different solutions, the salt solution will cause the steel wool to require the least amount force to rip apart. Hypothesis supported based on my results