A 132 mL of gas is measured at 38 C. If the pressure remains constant, what will be the volume given of the gas at 10'C?

 A 132 mL of gas is measured at 38 C. If the pressure remains constant, what will be the volume given of the gas at 10'C?

Answer

This problem is solved using either the General Gas Law equation or a simplified version called Charle’s Law. Charle’s Law is a simplification of the General Gas Law, but pressure is constant. I’m going to say this before solving the problem: In gas law problems temperatures must be in Kelvin (K), an absolute temperature scale.

Here’s Charle’s Law: V1/T1 = V2/T2 (temperature in kelvins)

(Me and my big mouth—-the General Gas Law equation is:
P1 x V1 /T1 = P2 x V2 /T2 (temperature in kelvin) …and before you ask, Charle’s Law applies when pressure is constant, so P1 cancels out P2 and you are left with the Charle’s Law formula .

Solving: Since temperature is not constant, lets convert from Celsius to Kelvins now. The conversion is: K = C + 273
T1 is 38C, in K that is K = 38 + 273 = 311
T2 is 10C,………K=C+273 K = 10+273 = 283

Now we will use Charles’ Law to get the answer:
132/311 = V2/283
v2 = 120.116….mL