Certain metal ions, particularly those with double and triple charges, interfere with the ability of soap to make suds. Hard water causes soap to precipitate, as evidenced by a bathtub ring. Calcium, magnesium, and iron ions are commonly found in hard water. Detergents have largely replaced laundry soap because of their ability to make suds in hard water. However, even detergents are affected by the presence of multicharged cations.
Ligands are molecules or ions that can bond to cations by donating a pair of electrons.
They are particularly effective at forming complexes with multicharged cations. To investigate the effect of metal ions on detergents and how EDTA alleviates that effect. Dispose of materials as directed by your instructor. Keep away from eyes and skin. I Fill each test tube with 3.0 mL of detergent solution.