MgCO
3
(
s
) ⇋ MgO(
s
) + CO
2
(
g
)
K
= [CO
2
]
PbCl
2
(
s
) ⇋ Pb
2+
(
aq
) + 2Cl
−
(
aq
)
K
= [Pb
2+
][Cl
−
]
2