If crystal growth does not start on its own after the solution in the flask returns to room temperature, identify the best ways to promote this process. a. Add ice cubes to the solution.
b. Scratch the bottom of the flask gently with a stirring rod.
c. Add a bit of solid as a seed crystal.
d. Place the flask on a hot plate to evaporate some solvent.

At a certain temperature the rate of this reaction is first order in hi with a rate constant of : 0.0632s2hig=h2g+i2g suppose a vessel contains hi at a concentration of 1.28m . calculate how long it takes for the concentration of hi to decrease to 17.0% of its initial value. you may assume no other reaction is important. round your answer to 2 significant digits.