Answer : The final temperature of gas is 266.12 K
Explanation :
According to the Joule-Thomson experiment, it states that when a gas is expanded adiabatically from higher pressure region to lower pressure region, the change in temperature with respect to change in pressure at constant enthalpy is known as Joule-Thomson coefficient.
The formula will be:

or,

As per question the formula will be:
.........(1)
where,
= Joule-Thomson coefficient of the gas = 
= initial temperature = 
= final temperature = ?
= initial pressure = 200.0 atm
= final pressure = 0.95 atm
Now put all the given values in the above equation 1, we get:


Therefore, the final temperature of gas is 266.12 K