We have an initial pressure of P1= 2.12 atm, and an initial temperature of T1= 21C, an unknown final pressure P2= x, and a final temperature of T2= 79C.
All of these fit perfectly into the Gay Lussac's Law formula of (P1)(T1)=(P2)(T2)
The temperatures have to be in Kelvin so remember to add 273 to your temperatures to make them from C to K.
All we have to do to isolate P2 is divide the (P1)(T1) by (T2) giving us the formula: (P1)(T1)/(T2)=(P2)
Your units of K cancel out and you're left with a pressure in atm.
Hi @tylerh61! You were right to use the Gay-Lussac's law but the actual equation for it is P1/T1=P2/T2 instead of (P1)(T1)=(P2)(T2)
Calculating it we get
P2= 2.53823 atm