If a gas at 740 mm hg and 70c has its pressure lower to 720 mm hg, what will it's temperature be if volume is held consistent

When the volume and quantity of the gas are held constant, we can use the Gay-Lussac's Gas Law expressed as
     P1/T1 = P2/T2
in which if the pressure of the gas decreases, we know that the temperature decreases.
We first convert the temperature to absolute temperature
     T1 = 70 + 273 = 343 K
Rearranging the Gay-Lussac's equation to solve for the final temperature 
     T2 = P2T1 / P1
           = (720 mmHg)(343 K) / 740 mmHg
           = 334 K = 61ºC

Bet

Explanation: