A sample of hydrogen gas at 127 degrees celsius has a pressure of 2.00 atm. at final temperature, in degrees celsius, will the pressure of the H2 decrease to .25 atm, if v and n do not change?

The temperature will decrease to 50 K

Explanation:

Step 1: Data given

Temperature = 127 °C = 400 K

Pressure = 2.00 atm

The pressure decreases to 0.25 atm

Volume and number of moles do not change

Step 2: Calculate the new pressure

p1/T1=p2/T2

⇒with p1 = The initial pressure = 2.00 atm

⇒with T1 = The initial temperature = 127 °C = 400 K

⇒with p2 = the new pressure = 0.25 atm

⇒with T2 = the new temperature = TO BE DETERMINED

2.00 atm / 400 K = 0.25 atm / T2

0.005 = 0.25 / T2

T2 = 0.25/0.005

T2 = 50 K

The temperature will decrease to 50 K