Hi, According to Charles gas law if you keep a certain constant pressure & moles of gas, you can relate the other 2 physical quantities (Volume & Temperature) in a formula: V/T=c If you increase T, V will increase because the temperature is directly proportional to the volume. The same happens if you decrease T, V will decrease. Now I cant understand how to start with V instead of T. How do you increase the Volume without changing the pressure ( because it must be constant) so that the temperature increases? Thanks in advance!!