Which of the following is the best example of chemical weathering? a: limestone rocks dissolving in water b: plant roots growing through concrete and splitting it c: waves carrying sand away from a beach d: a large rock splitting into pieces because of ice

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.