题干

加热N2O5,依次发生分解反应:①N2O5(g)⇌N2O3(g)+O2(g)、②N2O3(g)⇌N2O(g)+O2(g).在体积为2L的恒容密闭容器中充入8mol N2O5,加热到T℃时O2和N2O3的物质的量分别为9mol、3.4mol,则T℃时
c
(
N
2
O
3
)
c
(
O
2
)
c
(
N
2
O
5
)
为(   )

A:10.7

B:8.5

C:9.6

D:10.2

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B

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