Which process is endothermic?A.     CH4(g)+2O2(g)→CO2(g)+2H2O(g)B.     HCl(aq)+NaOH(aq)→NaCl(aq)+H2O(l)C.     CaCO3(s)→CaO(s)+CO2(g)D.

An endothermic process is one that absorbs heat from its surroundings. This means the reaction will take in heat from its environment, causing the temperature of the surroundings to decrease.

Let's analyze each of the given reactions:

A. CH4(g)+2O2(g)→CO2(g)+2H2O(g) This is a combustion reaction, which is typically exothermic because it releases heat.

B. HCl(aq)+NaOH(aq)→NaCl(aq)+H2O(l) This is a neutralization reaction, which is also typically exothermic because it releases heat.

C. CaCO3(s)→CaO(s)+CO2(g) This is a decomposition reaction. The decomposition of Calcium Carbonate is an endothermic process because it requires heat to break down the compound.

D. This option is not provided.

Therefore, the endothermic process among the given options is C. CaCO3(s)→CaO(s)+CO2(g).