Question

49. A gas at 27°C and pressure of 30 atm is
allowed to expand to atmosphere pressure and
volume 15 times larger. The final temperature
of the gas is.....
-123°C 2) 123°C 3) -132°C 4) 132°C​

Answer 1

Answer:  -123 degrees celsius

Explanation:from ideal gas equation, PV = nRT

So, T=  

nR

PV

​  

 

Since, n is constant, and R is also constant, we can say that T is directly proportional to the product of P and V

TαPV

volume is made 15 times and pressure is reduced to  

30

1

​  

 th of it's original value (initial pressure = 30 atm and final pressure = 1 atm)

So, temperature becomes 15 x  

30

1

​  

 times = 0.5 times it's initial value

Initial temperature = 27  

∘

C = 300K

So, final temperature = 0.5 x 300 K = 150 K = -123  

∘

C = -123 degrees celsius