Answer:
The pressure changes from 2.13 atm to 1.80 atm.
Step-by-step explanation:
Given data:
Initial pressure = ?
Final pressure = 1.80 atm
Initial temperature = 86.0°C (86.0 + 273 = 359 K)
Final temperature = 30.0°C (30+273 =303 K)
Solution:
According to Gay-Lussac Law, 
The pressure of given amount of a gas is directly proportional to its temperature at constant volume and number of moles. 
Mathematical relationship: 
P₁/T₁ = P₂/T₂ 
Now we will put the values in formula: 
P₁ = P₂T₁ /T₂ 
P₁ = 1.80 atm × 359 K / 303 K 
P₁ = 646.2 atm. K /303 K 
P₁ = 2.13 atm 
The pressure changes from 2.13 atm to 1.80 atm.