# Chemistry

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The decomposition of IBr(g)into I2 (g) and Br2 (g) is first order in IBr with k = 0.00255/sec.

(a)Starting with [IBr] = 1.50M, what will [IBr] become after 2.50 minutes?

(b)How long, in minutes, will it take for [IBr] to go from 0.500M to 0.100M?

(c)What is the half-life for this reaction in seconds?

(d)Enough IBr is added to an evacuated container to make [IBr] = 0.350M. How long will it take [I2] = 0.100M?
(e) The following mechanism has been proposed for the reaction above:

(step 1)IBr (g) ¨ I (g) + Br (g)(step 2)IBr(g) + Br (g) ¨ Br2(g) +I (g)(step 3)I (g) + I (g) ¨ I2 (g)

Based on the rate law described above, which step is the rate-determining step? ______________

What is the molecularity of the rate-determining step? _____________________

• Chemistry - ,

a)
ln(No/N) = akt
No = 1.5M
solve for N
a = 2
k = 0.00255
t = 2.5 min changed to seconds.

b)
same as in (a) but solve for t.

c)
Make No = 1.5 and
N = 1/2 that, solve for t.

• Chemistry - ,

0.490mol {\rm mol} magnesium fluoride