Calculate the enthalpy change for the following reaction: N2H4(g)+O2(g)→N2(g)+2H2O(l), ΔHrxn∘=? Given the following enthalpies of formation: N2(g)+2H2(g)→N2H4(g), ΔH1=95.4kJ H2(g)+1/2O2(g)→H2O(l), ΔH2=−285.8kJ

answer : a model is often used to explain and make things easier to understand when any scientific topic needs to be demonstrated and explained.

as in this case where a scientist wants to use a model to present the results of his detailed scientific investigation. he should do it as it will him to make the audience understand the concept in a much better way. also, it can be changed according to new scientific understandings.