# Problem: Dinitrogen pentoxide decomposes in the gas phase to form nitrogen dioxide and oxygen gas. The reaction is first order in dinitrogen pentoxide and has a half-life of 2.81 h at 25oC. If a 1.6-L reaction vessel initially contains 750 torr of N2O5 at 25 oC, what partial pressure of O2 will be present in the vessel after 220 minutes?

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###### FREE Expert Solution

We’re being asked to calculate partial pressure of O2 will be present in the vessel after 220 minutes.

The given equation is: N2O5(g) → NO2(g) + O2(g)

Balancing the equation is: N2O5(g) → 4 NO2(g) + O2(g)

The integrated rate law for a first order reaction is as follows:

where:

[A]t = concentration at time, t
k = decay constant
t = time
[A]0 = initial concentration

Also, recall that half-life is the time needed for the amount of a reactant to decrease by 50% or one-half

The half-life of a first-order reaction is given by:

We first need to calculate for the decay constant using the given half-life, 2.81 hr:

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###### Problem Details

Dinitrogen pentoxide decomposes in the gas phase to form nitrogen dioxide and oxygen gas. The reaction is first order in dinitrogen pentoxide and has a half-life of 2.81 h at 25oC. If a 1.6-L reaction vessel initially contains 750 torr of N2O5 at 25 oC, what partial pressure of O2 will be present in the vessel after 220 minutes?

What scientific concept do you need to know in order to solve this problem?

Our tutors have indicated that to solve this problem you will need to apply the Integrated Rate Law concept. You can view video lessons to learn Integrated Rate Law Or if you need more Integrated Rate Law practice, you can also practice Integrated Rate Law practice problems .

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What professor is this problem relevant for?

Based on our data, we think this problem is relevant for Professor Liwosz's class at UB.