In the use of resins, it's sometimes necessary to distinguish between different types of resins. Below, our editor shares a simple and feasible identification method.

Step 1:

A. Take 2mL of the resin sample, place it in a 30mL tube, and remove the adherent water from the resin.

Add 5 mL of 1 mol/L HCl, shake for 1-2 minutes, and then remove the upper clear liquid of the resin. Repeat this process 2-3 times.

Rinse with pure water, shake, then remove the upper clear liquid. Repeat this process 2-3 times.

Add 5 mL of 10% CuSO4 solution, shake for 1 minute. Rinse thoroughly with pure water as per C.

Step Two:

After the first step of processing, if the resin changes color to light green, add 2 mL of 5 mol/L NH4OH solution, shake for 1 minute, then rinse thoroughly with pure water before observing.

If the resin darkens (to a deep blue) after the aforementioned treatment, it is a strong acidic cation exchange resin. If the resin retains its color (remaining light green), it is a weak basic anion resin.

Step 3:

After the first step, if the resin does not change color, proceed with the following steps:

Add 5mL of 1mol/L NaOH, shake for 1 minute, and then thoroughly rinse by decantation.

Add 5 drops of phenolphthalein, shake for 1 minute, and rinse thoroughly with pure water.

After the aforementioned treatment, if the resin appears red, it is a strongly alkaline anion exchange resin.

Step Four:

After the third step, the resin remains unchanged in color. Proceed as follows:

Add 5 mL of 1 mol/L HCl, shake for 1-2 minutes, then rinse with pure water 2-3 times.

Add 5 drops of methyl red, shake for 1 minute, and thoroughly rinse with pure water.

After the above treatment, if the resin is a peach red, it is a weakly acidic cation exchange resin. If the resin remains unchanged after treatment, it has no ion exchange capability.