Question

The gas law for an ideal gas at absolute temperature T (in kelvins), pressure P (in atmospheres), and volume V (in liters) is PV = nRT, where n is the number of moles of the gas and R = 0.0821 is the gas constant. Suppose that, at a certain instant, P = 8.0 atm and is increasing at a rate of 0.14 atm/min and V = 13 L and is decreasing at a rate of 0.16 L/min. Find the rate of change of T with respect to time at that instant if n = 10 mol. (Round your answer to four decimal places.)


`(dT)/(dt)` = _____ K/min

Answer 1

The temperature of the gas is increasing 0.6577 kelvin/min

Explanation:

We have to find the rate of change of T with respect to time at that instant so we should start by arranging the equation
`T=(PV)/(nR)`

Now we can derivate T to obtain T'

`T'=((PV)'(nR)-(PV)(nR)')/(((nR)^(2) )`

Now we should solve the derivate of (PV) and (nR) by using the product rule

`T'=((P'V+PV')(nR)-(PV)(n'R+nR'))/((nR)^(2) )`

We know that

P=8atm

V=13L

P'=0.14

V'=-0.16

n=10

R=0.0821

n'=0

R'=0

We substitute into the equation

`T'=((0.14*13+8*-0.16)(10*0.0821)-(8*13)(0*0.0821+10*0))/((10*0.0821)^(2) )`

`T= 0.6577`