Prepare 25 mL of a 0.35 M aqueous solution of hexamethylenediamine (1,6-hexanediamine). For example, you would need 1.0 gram of 1,6-hexanediamine in 25 mL of water to make a 0.35 M solution. To do this, weigh out the solid 1,6- hexanediamine on paper using a balance.