Answer:
if volume is increased, the number of collisions per second decreases.
Explanation:
volume is inversely proportional to pressure. Increase in volume leads to decrease in pressure and decrease in volume leads to increase in pressure.
if the pressure is high, it leads to increase in the number of collisions. If the pressure is low, it leads to decrease int he number of collisions.
therefore since volume is inversely proportional, when volume is increased, the pressure decreases and thus the number of collisions decreases.