Which statement about decalcification methods is true?

• A. Ion exchange resin and electrolyte methods fall under acid methods.
• B. Heating the decalcification solution speeds decalcification.
• C. Decalcification cannot involve acids.
• D. Chelating agents are considered the same as acid methods.

Answer: (A)

Decalcification methods are grouped into acid methods and non-acid methods. Ion exchange resin decalcification uses a resin that exchanges calcium ions for hydrogen ions, introducing acidity into the solution and speeding mineral dissolution; the process effectively relies on an acidic environment, so it is considered an acid method. Electrolytic decalcification also promotes calcium removal under conditions that support proton activity or acidic surroundings, placing it in the same acid-method category.

Heating can speed many chemical processes, but in decalcification it isn’t universally reliable because higher temperatures can hasten over-decalcification and damage tissue, so speed is balanced with tissue preservation. Decalcification can involve acids, so saying it cannot involves acids isn’t correct. Chelating agents remove calcium by forming stable complexes rather than dissolving minerals with acid, so they are not the same as acid methods.