[bluepink]

H2(g)+I^2(g) --->2HI(g)
Step 2 is the rate determining step
Thus, Rate = k'[H2(g)][I(g)]2

CAN THE ORDER OF REACTION BE DETERMINED IN THE BALANCED EQUATION?
ISN'T IT NEED TO BE DETERMINED BY DOING THE EXPERIMENT?
I DON'T UNDERSTAND HOW CAN I ACHIEVE THE ABOVE ANSWER.
THX

[Astrokel]

Look at the mechanism(slow step) to determine the rate law. The stoichiometric ratio of the reactants in the slowest step is the order of that reactants.

When a mechanism is proposed, you will hope that it tally with your experimently determined rate law.