diagram a @ 0 min: 8 red circles
diagram b @ 1 min: 6 red circles, 2 blue circles
diagram c @ 2 min: 4 red circles, 4 blue circles
question 1: what is the order of the reaction?
how am I to know this? i don't have reaction rates to compare to my changes in concentration?
Well red and blue circles seem bit confusing. Let's simplify it.
Imagine there is this reaction taking place R
B
Initially, [R] = 8 and [B ] = 0
As you have mentioned, you have to calculate reaction rate to determine the order of reactant.
So at the 1st min, the reaction rate would be -(6-8)/1 = 2
2nd min, the reaction rate would be -(4-6)/1 = 2
What does a constant reaction rate tells you about the order of [A] if you were to compare it against with the concentration?