Which of the following expressions is the correct equilibrium-constant expression for the reaction below? 2 Pb(NO 3
) 2
( s)⇌2PbO(s)+4NO 2
( g)+O 2
( g) A. k[Pb(NO 3
) 2
] 2
B. 4[NO 2
]+[O 2
] C. [NO 2
] 4
⋅[O 2
] D. [NO 2
] 4
⋅[O 2
]⋅[PbO] 2
/[Pb(NO 3
) 2
] 2
E. None of the above