If the pressure on 100 c.c. of air is halved, then its volume (at the same temperature) would be __________ c.c.

ANS:D - 200

According to Boyle's Law, which states that at constant temperature, the pressure of a given amount of gas is inversely proportional to its volume, if the pressure on 100 c.c. of air is halved, its volume would double. So, if the pressure is halved, the volume would become 2×100 c.c.=200 c.c.2×100c.c.=200c.c.. Therefore, the correct answer is 200 c.c.