# Dynamic equilibrium ICE table and K

#### meehti

Im trying to find a shortcut to save time and i wanna know is it able to do the calculation like this?
The question is:
At temperature 1100 K is the dynamic equilibrium constant, K = 25.0 for equilibrium

Reaction: H2(g) + I2(g) ↔ 2HI(g)

In a equilibrium mixture is the concentration of hydrogen 9,2 . 10-2 mol/dm3 & concentration of iodide is
2,0 . 10-3 mol/dm3. Calculate the concentration of Hydrogen iodide
[9.2x10^-2]*[2x10^-3] = 1.8x10^-4
I will write [H2] * [I2] as 1.8x10^-4
K= 25M^-2
K = product /reactants
the relation between K & Product
[1.8x10^-4] * 25M = 4.5x10^-3

my answer is 4.5x10^-3 is the [HI] concentration

Is this correct or incorrect?

#### studiot

Doesn't look like a very short cut to me compared to the proper way of laying it out.

Furthermore if your instructor is as puzzled as I am over what you have done then she will think you are not interested in Chemistry and just mark you down.

Whem learning, it is important to show and justify all your steps, not least becasue if you get the arithmetic wrong but have the method correct you will only loose a mark or so for sloppy arithmetic.
But if you only offer incorrect arithmetic all the marker can do is to say "The candidate got it wrong. No marks"

• topsquark

#### meehti

I have already passed all my chemistry classes (biochemistry) im switching school and I have to proceed with the same procedur as the freshmen even if im starting 5th grade
It was 3 years ago i had biochemistry or chemistry and I used to have many short cuts to answer without fully understanding them
However the question i need answer on is if the answer is correct not the calculation
What is the HI concentration?