Browse Questions

The number of moles of lead nitrate needed to coagulate 2 mol of colloidal $[AgI]I^-$ is

(a) 2
(b) 1
(c) 1/2
(d) 2/3

$2[AgI]I^- + Pb^{2+} \longrightarrow PbI_2 + 2AgI$
Thus, 2 moles of $[AgI]I^-$ are coagulated by 1 mole of $Pb^{2+}$ i.e., 1 mole of $Pb(NO_3)_2$.