When air in a syringe is compressed such that there is no change in temperature, the

A.

air liquefies

B.

pressure increases

C.

intermolecular space increases

D.

density decreases

Correct answer is B

Since the temperature of air remain constant.So, it is a isothermal process.
PV=K
This eq. shows that on increasing pressure, the volume gets reduced and vice-versa.
Since the syringe is slowly compressed, volume is decreasing.
Therefore, the pressure inside the syringe will increases because the molecules now hit the syringe walls more frequently.