The data below were collected for the following reaction at 500 ^\circ {\rm C}:
{\rm{CH}}_3 {\rm{CN(}}g)\; \rightarrow \;{\rm{CH}}_3 {\rm{NC(}}g)
Time(h) [CH3CN]
0.0 1.000
5.0 0.794
10.0 0.631
15.0 0.501
20.0 0.398
25.0 0.316

Determine the value of the rate constant at this temperature.

What is the half-life for this reaction (at the initial concentration)?

How long will it take for 84% of the {\rm{CH}}_3 {\rm{NC}} to convert to {\rm{CH}}_3 {\rm{CN}}?

If a reactant was removed, did the new equilibrium system shift to make more reactants or more products?

The difference between the atomic number of an element and the element’s atomic mass is the number of ions.

Two nitro no2 groups are chemically bonded to a patch of surface. they can't move to another location on the surface, but they can rotate (see sketch at right). it turns out that the amount of rotational kinetic energy each no2 group can have is required to be a multiple of ε, where =ε×1.010−24 j. in other words, each no2 group could have ε of rotational kinetic energy, or 2ε, or 3ε, and so forth — but it cannot have just any old amount of rotational kinetic energy. suppose the total rotational kinetic energy in this system is initially known to be 32ε. then, some heat is removed from the system, and the total rotational kinetic energy falls to 18ε. calculate the change in entropy. round your answer to 3 significant digits, and be sure it has the correct unit symbol.