Question

This is my second time asking this question it was written in a marker which is crazy I wanted my answer to be typed nicely i hope you guys are not charging me for this question Write the chemical equation for the decomposition of hydrogen peroxide. Include heat in the equation to indicate whether the reaction was endothermic or exothermic. Give three examples of decomposition reactions shown by balanced chemical equations. I asked this question last night and it was written in a mess with marker

Answer 1

The decomposition of hydrogen peroxide is an exothermic reaction, usually gives a small amount of heat at room temperature.

thus the equation is

2 H2O2 (l) ----------------> 2H2O(l) + O2(g) + heat

or

2 H2O2 (l) ----------------> 2H2O(l) + O2(g) ; Delta H = negative

The other 3 examples of decomposition are

1) decomposition of water by electrolysis to H2 and O2

2H2O(l) ------------> 2H2 (g) + O2(g)

2) the decomposition of limestone on heating

CaCO3(s) ------------> CaO (s) + CO2(g)

3) The frothing of cool/carbonated drinks where the carbonic acid them decomposed to give water and CO2

H2CO3(aq) ------------> H2O(l) + CO2(g)

All the 3 examples given are endothermic( they absorb heat)