ANSWER
The new pressure of the gas is 1.3atm
Step-by-step explanation
Given that;
The initial temperature of the gas is 20 degrees celcius
The final temperature of the gas is 35 degrees celcius
The initial pressure of the gas is 1.2 atm
Follow the steps below to find the final pressure of the gas
Step 1; Convert the temperature to degrees Kelvin using the below conversion formula


Step 2; Apply the Gay Lussac's law

Substitute the given data into the above formula

Therefore, the new pressure of the gas is 1.3 atm