A flask is charged with 0.140 mol of A and allowed to react to form B according

Question

A flask is charged with 0.140 mol of A and allowed to react to form B according to the following hypothetical gas-phase reaction. A(g) B(g) The following data are collected. times (s) 0 40 80 120 160 moles of A 0.140 0.068 0.049 0.031 0.019 (a) Calculate the number of moles of B at each time in the table. 0 s mol 40 s mol 80 s mol 120 s mol 160 s mol (b) Calculate the average rate of disappearance of A for each 40 s interval, in units of mol/s. 0 - 40 s mol/s 40 - 80 s mol/s 80 - 120 s mol/s 120 - 160 mol/s mol/s

Explanation / Answer

moles B are(0.1-0.067), (0.1-0.045) and so on. For the first two readings 0.033 mol of A have vanished in 40 s, so 8.25 x 10^-4 mol s-1. For readings 2 and 3 0.022 mol of A have vanished, so proceed like this and average 2a The rate does not depend on [A], so changing [A] will have no effect. The rate constant will only change if the temperature changes. b The order of a reaction in a particular component = the exponent to which the concentration of that component is raised in the rate law, overall order = sum of individual orders, so the reaction is zero order in A, second order in B, second order overall c Units of k are rate/concentration^2

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.