Reversible process or reaction is those that can be reversed by an infinitesimally small change in conditions. For example, ice and water coexist at 101 325 Pa and 0 °C; a very slight temperature increase causes the ice to melt; a tiny temperature decrease causes the water to freeze. Melting or freezing under these conditions can be considered reversible.
Generalic, Eni. "Reversible process." Croatian-English Chemistry Dictionary & Glossary. 29 June 2022. KTF-Split. {Date of access}. <https://glossary.periodni.com>.
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