The following reaction takes place in a sealed 50.0-L container at a temperature of 150°C.

Question

4 NH3(g) 5O2(g) → 4NO(g) 6H2O(g)

a) When 34.0 g of NH3 reacts with an excess of O2, what is the partial pressure (in kPa) of NO in the container?

b) Which of the four above gases effuses the fastest? Show your work to explain your answer

Answer 1

first let's find the moles of NH3:

34 g of NH3 @ 17 g/mole = 2.00 moles of NH3

since it's a 1 to 1 ratio  for NH3 making NO,

2.00 moles of NH3 prodeuces 2.00 moles of NO

so let's find the pressure you asked for:

PV=nRT

P (50.0 Litres) = 2.00 mol (8.31kPa-L/mol-K)(423K)

P = 140.7 kPa

your answer (3 sigfigs) is : 141kPa

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the efussion rate depends upon mass, the lighter it is... the faster it travels:

NH3 (17g/mol)

O2 (32g/mol)

NO (30 g/mol)

H20 (18 g/mol)

Your answer is: NH3 effuses the fastest