What is the new temperature (in degree Celsius) after the sample is transferred to a new container with a volume of 2.65 L and a pressure of 1.26 atm?
You have not mentioned the original temperature, pressure and volume in your question. That does not allow me to give you an exact answer. Instead, I will provide an expression in which you can substitute the original values to get the new temperature.
Let the original temperature be To, the original volume Vo and the original pressure Po.
Apply the Ideal gas law which states that P*V = n*R*T, where P is the pressure, V is the volume, n is the amount of the gas in moles, R is a constant and T is the temperature.
As the amount gas does not change when it is shifted to the new container, we can write the gas law as: P*V/T = n*R = constant.
The new values, and the original values can be equated in the following manner: Po*Vo/To = 1.26*2.65/Tf, where Tf is the new temperature.
Tf = To*2.65*1.26/Po*Vo
Tf = (2.65*1.26)*(To/Po*Vo)