Answer:
28.108 K.
Step-by-step explanation:
Given: Pressure (P)= 1.2atm
Number of moles (n)= 2.6 moles
Volume (V)= 5.00-L
Now finding the temperature (T).
Formula; T= 
R is a constant factor which makes other factors work together.
There is a numerical value for R which we use is 
∴ Temperature (T)= 
⇒ Temperature (T)= 
∴ Temperature is 28.108 K