Answer:
Approximately .
Assumption: there's no temperature change.
Explanation:
Refer to a modern periodic table for the relative atomic mass data:
- N: ;
- O: .
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Number of moles of in that sample of :
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Concentration of in that container:
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Construct a RICE table for this equilibrium. Note that all values in this table shall stand for concentrations. Let the change in the concentration of be .
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The equilibrium concentrations shall satisfy the equilibrium law for this reaction under this particular temperature.
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This equation can be simplified to a quadratic equation. Solve this equation. Note that there might be more than one possible values for . itself might not necessarily be positive. However, keep in mind that all concentrations in an equilibrium should be positive. Apply that property to check the -value.
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What will be the concentration of that additional of if it was added to an evacuated flask?
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The new concentration of will become
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Construct another RICE table. Let the change in the concentration of be .
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Once again, the equilibrium conditions shall satisfy this particular equilibrium law.
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Simplify and solve this equation for . Make sure that the -value ensures that all concentrations are positive.
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Note that for if that would lead to a negative value for the concentration of .
Hence the equilibrium concentration of will be:
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