Decomposing in analytical chemistry means that a certain substance is converted, by melting it with a suitable melting medium (sodium carbonate, sodium hydroxide, sodium peroxide, ...) in the kind of compound which will afterwards that dissolve in water, acid or base very easily.
Generalic, Eni. "Decomposing." Croatian-English Chemistry Dictionary & Glossary. 29 June 2022. KTF-Split. 2 Apr. 2025. <https://glossary.periodni.com>.
Glossary
Periodic Table