Question

# The decomposition reaction given below: 2 IF5(g) 1 I2(g) + 5 F2(g) is carried out in...

The decomposition reaction given below: 2 IF5(g) 1 I2(g) + 5 F2(g) is carried out in a closed reaction vessel. If the partial pressure of IF5(g) is decreasing at the rate of 144 torr/min, what is the rate of change of the total pressure in the vessel? Delta Ptot /delta t = ___torr/min

From the balanced reaction

2IF5(g) ------> I2(g) + 5F2(g)

It is given that

Partial pressure of IF5(g) is decreasing at the rate of 144 torr/min

Since moles ratio of IF5 and F2 is 2:5

The increase in the partial pressure of 5mol F2 =

rate of increase partial pressure of F2 = 360 torr/min

Since mole ratio of I2 and IF5 = 1:2

Rate of increase of pertial pressure of I2 =

=72 torr/min

So sum of partial pressure increasing rate = 360 + 72 = 432 torr/min

But 2mol IF5 is partial pressure rate is decreasing

so we have to subtract it from the above sum

Rate of change of total partial pressure = 432 - 144 = 288 torr/min