The branch of chemistry that deals with the relationships between heat and chemical reactions.

ऊष्मागतिकी

English Usage: "Thermochemistry is essential for understanding how energy changes during chemical reactions."

Hindi Usage: "ऊष्मागतिकी को समझना रासायनिक अभिक्रियाओं के दौरान ऊर्जा के परिवर्तनों को समझने के लिए अनिवार्य है।"