Acetonitrile is a useful polar aprotic solvent and carbon building block for org
ID: 1011317 • Letter: A
Question
Acetonitrile is a useful polar aprotic solvent and carbon building block for organic synthesis. We will let A = methyl isonitrile (CH_3NC) and B acetonitrile (CH_3CN). Acetonitrile (B) can be produced by a rearrangement of methyl isonitrile (A). This isomerization reaction is first-order in the concentration of methyl isonitrile (-r_A = kc_A with rate constant k = 2.0 times 10^4/s. Suppose that acetonitrile (B) is to be produced in a well-agitated (i.e., well-mixed and therefore spatially uniform in reactor), constant volume. 7.0 L batch reactor. The reactor is initially charged with 15.0 mol methyl isonitrile (A) in a solvent, and no B. How long will it take to produce 3.0 mol acetonitrile (B)? for a SPICEY table. t =______hoursExplanation / Answer
initial CH3NC concentration = 15.0 / 7.0 = 2.14 M = Ao
after some time molarity of CH3CN = 3.0 / 7.0 = 0.429 M
remaining concentration = At = 2.14 - 0.429 = 1.71 M
rate constant = k = 2.0 x 10^-4 s-1
t = 1/ k * ln (Ao / At)
t = 1/2.0 x 10^-4 * ln (2.14 / 1.71)
t = 1121.56 sec
t = 0.312 hours