Question

importantes de form a The conversion of methylisonitrile to acetonitrile in the gas phase at 250 °C CH,NC() CH,CN) is first order in CHANC with a rate constant of 3.00x10 ! If the initial concentration of CHANC is 4.65x10M, the concentration of CHANC will be 1.22*10° Matter ted have passed Submit Answer Roty Entire Group 3 more group attempts remaining

Answer 1

We know for 1st order reaction, rate constant,

K = (2.303 / t) * log ([initial concentration of reactant] / [final concentration of reactant]) ,where t is time

Now, for the 1st problem given that, rate constant = 3.00 * 10-3 S-1

Initial concentration of reactant CH3NC = 4.65 * 10-2 M

Final concentration of reactant CH3NC = 1.22 * 10-2 M

Hence from the given equation

3.00 * 10-3 S-1 = (2.303 / t) * log (4.65 * 10-2 M / 1.22 * 10-2 M)

or, time, t = (2.303 / 3.00 * 10-3 S-1) * log (4.65 * 10-2 M / 1.22 * 10-2 M)

= 767.77 S * 0.58

= 446.08 S

So after 446.08 Sec. concentration will droped from 4.65 * 10-2 M to 1.22 * 10-2 M.

For 2nd problem given that

Initial concentration of reactant N2O5 = 7.55 * 10-2 M

Final concentration of reactant N2O5 = 8.53 * 10-3 M

time taken for this conversion = 348 Sec

Hence from the equation rate constant K = (2.303 / 348 S) * log ( 7.55 * 10-2 M / 8.53 * 10-3 M)

= 6.6178 * 10-3 sec-1 * 0.947

= 6.267 * 10-3 sec-1

So rate constant of the given reaction is 6.267 * 10-3 sec-1.