Calculate the pressure of the NO produced in the reaction if it is transferred to a 1.68-L flask and cooled to 29 °C.

Question

A sample of O₂ with a pressure of 1.96 atm and a volume of 288 mL is allowed to react with excess N₂ at 129 °C.

1.  N₂ (g) +  O₂ (g) 2 NO (g)  

Calculate the pressure of the NO produced in the reaction if it is transferred to a 1.68-L flask and cooled to 29 °C.

______ atm

Answer 1

This is a multistep problem:

It should be noted that when dealing with gasses, the gas equation (PV=nRT) should be used.

1. Find the moles of O₂ used in the reaction, by solving for n and using the given information.
2. We can rearrange the equation to be n=(PV)/(RT)

P= 1.96 atm

V= 288 mL = 0.288 L

R= 0.082057 (L x atm)/(K x mol)

T= 129 C = 402 K

1. After solving for n moles of O₂, the moles of NO can be found using the molar ratio of the equation.

n moles of O₂ x (2 moles of NO/1 mole of O₂) = ___ moles of NO

1. Finally, the gas equation can be used again. This time, find the pressure of NO in the reaction, by solving for P and using the given information and the moles of NO.
2. We can rearrange the equation to be P=(nRT)/V
3. Remember units need to cancel.

After plugging in the values, the result will give you the pressure of NO.

I hope this helps!