A balloon having an initial temperature of 16.4°C is heated so that the volume doubles while the pressure is kept fixed. What is the new value of the temperature?

The general P,V,T equation (Boyles' + Charles' laws) can be written:




In this case P1=P2 so this simplifies to



Plug in the temperature (must be in Kelvins or Rankines -- the absolute temperature scale). You know that V2 = 2*V1 so replace V2 with that and solve for T2