Question

the decomposition of ammonium chloride into ammonia and oxygen is an exothermic reaction​

Answer 1

Answer:

Thermal decomposition means using 'heat' to 'break down' a molecule into smaller ones. ... The formation of ammonium chloride from ammonia and hydrogen chloride is exothermic (heat released or heat given out to the surroundings - the cooler parts of the test tube).

Answer 2

${\tt{\red{\underline{\underline{\huge{Answer:}}}}}}$

Ammonium chloride appears to sublime upon heating but actually decomposes into ammonia and hydrogen chloride gas. Ammonium chloride reacts with a strong base, like sodium hydroxide, to release ammonia gas.