Consider this reaction:
2HI(g) → H2(g)+ I2(g)

At a certain temperature it obeys this rate law.

Rate= 8.74 x 10^-4 s^1

Suppose a vessel contains HI at a concentration of 0.330M. Calculate the concentration of HI in the vessel 800 seconds later. You may assume no other reaction is important. Round your answer to significant digit

Explanation:

Hello,

In this case, based on the given units of the rate constant, it is a first-order reaction with respect to HI, therefore, the rate law is:

Whose integration turns out:

Therefore, the concentration of HI after 800 second finally result:

Best regards.

2fe + 3h2so4 -> fe2(so4)3 + 3h2

it is necessary to balance equations in order to get the proper amount of reactants as well as products in order not to make a miscalculation.

you cannot change the subscripts as that would change the substance itself. for instance, diatomic elements such as h2 only have the subscript two when a gas. another example would be so4, if you were to change the subscript, the element would no longer be sulfate.

we change the coefficients instead as that only changes the number of molecules rather than the substance itself.

hope this !