Explanation as well please

V1t2 = v2t1 is an expression of who’s law

Astudent pours 10.0 g of salt into a container of water and observes the amount of time it takes for the salt to dissolve. she then repeats the process using the same amounts of salt and water but this time she slowly stirs the mixture while it is dissolving. the student performs the experiment one more time but this time she stirs the mixture rapidly. the dependent variable in this experiment is: time for salt to dissolve speed of stirring amount of water mass of salt

Witch two conditions can limit the usefulness of the kinetic molecular theory in describing gas behavior?