Final answer:
The change in temperature of the gas is 69 °C.
Step-by-step explanation:
To find the change in temperature of the gas, you can subtract the initial temperature from the final temperature. In this case, the initial temperature is 17 °C and the final temperature is 86 °C. So, the change in temperature is 86 °C - 17 °C = 69 °C. Therefore, the change in temperature of the gas is 69 °C.