AP Chemistrymediummcq1 pt
For the decomposition 2N2O5 -> 4NO2 + O2, experiment shows that d[O2]/dt = +x at some instant. What is -d[N2O5]/dt at that instant?
A.2x
B.x/2
C.x
D.4x
Explanation
Core Concept
Rates of individual species are tied together through the stoichiometric coefficients. Every 2 moles of N2O5 consumed produce 1 mole of O2, so N2O5 disappears twice as fast as O2 appears. Writing -d[N2O5]/dt = 2 x (d[O2]/dt) gives 2x. Dividing each species' rate by its coefficient maps every one of them onto the same unique reaction rate.
Correct Answer
A2x
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