Question about water? for chemistry geniuses!!! (well probably anyone can answer it except me)?

Question

iron (III) ions in water reacting to potassium thiocyanate.

if the reaction is large then does that mean that there is a lot of iron in the water? and if a small reaction occurs then there is a small amount of iron in the water? why?
if you have a website so i can site it from it would be helpful but if you don't then it's fine.

Answer 1

Technically, a "large" reaction needs ALL reactants to be in higher concentration. So a lot of iron and very little of the thiocyanate, or a lot of thiocyanate and very little iron might appear almost the same.

Think of the old phrase, "It takes TWO to tango."