# Chemistry

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A reaction is first order and it takes 324 minutes for the reaction to be 50.0% complete. How long will it take for the reaction to be 85.0% complete at the same temperature?

2. N2O5 decomposes to N2O4 and O2 and the reaction is first order in N2O5 with a specific rate constant of 6.22 x 10^ -4 sec^-1 at 45 C. What will be the initial rate of formation of oxygen if the concentration of N2O5 is 0.100 M?

• Chemistry -

1. k = 0.693/t1/2
solve for k and substitute into the following:
ln(No/N) = kt
I would use No = 100 (just an arbitrary number), then N would be 15 left if it was 85% complete. Solve for t.

• Chemistry -

Thank you so much. That makes more sense. I had in 85, not 15.

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