If 1.0 L of 1.5 mol/L sodium iodide, Nal, is hrixed with 1.25 L of a 1.7 mol/L silver nitrate, AgNO3, solution, to produce a precipitate of silver iodide, Agl, which is the
limiting reagent?

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.

its first and third is your answer i did the qustion the fourth isnt right