At a certain temperature the rate of this reaction is first order in HI with a rate constant of : 7.21/s2HI (g) = H2 (g) + I2 (g) Suppose a vessel contains HI at a concentration of 0.440M. Calculate the concentration of HI in the vessel 0.210 seconds later. You may assume no other reaction is important.

C HI = 0.0968 M

Explanation:

2HI (g) → H2 (g) + I2 (g) - ra = K (Ca) ∧α = - δCa/δt

∴ a: HI (g)

∴ order (α) = 1

∴ rate constant (K) = 7.21/s

∴ Initial concenttration HI (g) (Cao) = 0.440 M

∴ t = 0.210 s ⇒ Ca = ?

⇒ - δCa/δt = KCa

⇒ - ∫δCa/Ca = K*∫δt

⇒ Ln (Cao/Ca) = K*t

⇒ Cao/Ca = e∧ (K*t)

⇒ Cao/e∧ (K*t) = Ca

⇒ Ca = (0.440) / e∧ ((7.21*0,21))

⇒ Ca = 0.440/4.54533

⇒ Ca = 0.0968 M