Two glass bulbs of volumes 500 c.c and 200 c.c are connected by a narrow tube. These bulbs are filled with air at 17^(@)C and 750 mm of Hg pressure. If the small bulb and big bulb are placed in melting ice and boiling water respectively, find the pressure of the air in bulbs.

Two glass bulbs of volumes 500 c.c and 200 c.c are connected by a narr

1.	Two glass bulbs of volumes 500 c.c and 200 c.c are connected by a narrow tube. These bulbs are filled with air at 17^(@)C and 750 mm of Hg pressure. If the small bulb and big bulb are placed in melting ice and boiling water respectively, find the pressure of the air in bulbs.
Answer» Solution :If the two bulbs are at the same and temperature Total volume `V_(0)=V_(1)+V_(2)=500+200=700 cm^(3)`, Total mass of the gas = m Pressure `P_(0)=750mm` of Hg , Temperature `T_(0)=273+17=290K` From the gas equation, `P_(0)V_(0)=m/M""RT_(0)" (or) "(P_(0)V_(0))/T_(0)=m/MR"....(1)"` If the two bulbs are different temperatures let P be the temperature in the bulbs. For big bulb, `PV_(1)=m_(1)/M""RT_(1)` Here, `V_(1)=200CM^(3)" and "T_(1)=273+100=373K` For small bulb, `P_(2)=m_(2)/M""RT_(2)` Here, `V_(2)=200 cm^(3)" and "T_(2)=273K` `(PV_(1))/T_(1)+(PV_(2))/T_(2)=m_(1)/M""R+m_(2)/M""R=m""R/M` For gas equation, `(P_(0)V_(0))/T_(0)=(PV_(1))/T_(1)+(PV_(2))/T_(2)=P(V_(1)/T_(1)+V_(2)/T_(2))` `P=(P_(0)V_(0))/T_(0) times 1/(V_(1)/T_(1)+V_(2)/T_(2))=(750 times 700)/(290) times 1/((500/373+200/273))` `THEREFORE P=873mm` of Hg.