Answer : Normally in any chemical reaction, if the enthalpy change i.e. ΔH is positive which means it is greater than zero then it can be called as an Endothermic Reaction.
Whereas, the system under study is absorbing heat that is produced during the reaction. So if ΔH is found to be positive then it can be called as endothermic reaction.
Answer:
Copper(II) sulphate – sodium hydroxide reaction
The reaction between copper(Il) sulphate and sodium hydroxide solutions is a good place to start. If you slowly add one to the other while stirring, you will get a precipitate of copper(II) hydroxide, Cu(OH)2.
Answer: one molecule of O2.
Explanation: sweet i just took a guess but I believe that if 3 o2 molecules - 2 h2 molecules I think that its just basic maths and it is C because 3-2 = 1 and its o2 remaining, sorry if I’m wrong.