Thermodynamics

$2 \mathrm{H}_2 \mathrm{O}_{2(l)} \longrightarrow 2 \mathrm{H}_2 \mathrm{O}_{(l)}+\mathrm{O}_{2(\mathrm{~g})}$

$\mathrm{H}_{2(\mathrm{~g})} \longrightarrow 2 \mathrm{H}_{(\mathrm{g})}$

$\mathrm{CaCO}_{3(\mathrm{~s})} \xrightarrow{\Delta} \mathrm{CaO}_{(\mathrm{s})}+\mathrm{CO}_{2(\mathrm{~g})}$

$2 \mathrm{H}_{2(\mathrm{~g})}+\mathrm{O}_{2(\mathrm{~g})} \longrightarrow 2 \mathrm{H}_2 \mathrm{O}_{(\mathrm{l})}$