For a certain reaction, a plot of 1/[A] vs, time gives a straight line with a sl
ID: 1000140 • Letter: F
Question
For a certain reaction, a plot of 1/[A] vs, time gives a straight line with a slope of 20 (Ms)^-1 and a y -intercept of 2. What is the original concentration of A? A) 0.05 M B) 0.5 M C) 2 M D) 20 M E) Not enough information is given to solve the problem. 3) For the reaction 5CI^-(aq) 6 CIO_3(aq) + 6H^+(aq) rightarrow 3CI_2(g) + 3H_2O(l), it is found that the experimental rate law is zero order with respect to CI^-. Why does the concentration of CI^- have no effect on the rate? A) CI^- is an intermediate. B) The concentration of CI^- very small compared to the other reactants C) The fraction of molecules of CI^- that have large enough energies to overcome the activation energy is almost zero. E) CI^- must react in a step after the rate determine step. E) The activation energy for CI^- to react is very high.Explanation / Answer
The data on 1/A vs time suggests the reaction to be 2nd order whose slope is rate constant whose value is 20/M.S and intercept is 1/ Initial concentration as per the following equation
1/A= 1/AO+kt
A is concentration of A at any time and 1/AO is reciprocal of initial concentration
1/AO= 2
AO =0.5M ( B is correct)
The actual reaction is 6NaOH + 3Cl2 --> NaClO3 + 3H2O + 5NaCl
Cl- is an intermediate ( A) and Cl- reacts in a step after the rate determining step (D)