Question

When doing limiting reagents, how do you know when to put your answer in moles or grams?

Answer 1

depends on the question, usually its in moles though

Answer 2

how do you tell?

Answer 3

the question should imply/ask it. Like if its asking which is the limiting reagent, you have to compare the moles of each substance. if its asking how much of it you need for the reagents to completely react, its the grams.

Answer 4

how do you find the excess?

Answer 5

which one is not consumed by the reaction. forgot the way to solve it but basically you try to finish a reagent and see which one has excess. or you could determine how much of a reagent will it take to consume the other one and see which one is more.

like
2H2 + O2 => 2H2O

you can see whether it will take more moles of O2 or H2 to finish the reaction and determine from there