The first element of rare–earth metals is

$\left[\mathrm{PtCl}_{4}\right]^{2-}+\mathrm{H}_{2} \mathrm{O} \rightleftharpoons\left[\mathrm{Pt}\left(\mathrm{H}_{2} \mathrm{O}\right) \mathrm{Cl}_{3}\right]^{-}+\mathrm{Cl}^{-}$

was measured as a function of concentrations of different species. It was observed that

$\frac{-\mathrm{d}\left[\left[\mathrm{PtCl}_{4}\right]^{2-}\right]}{\mathrm{dt}}=4.8 \times 10^{-5}\left[\left[\mathrm{PtCl}_{4}\right]^{2-}\right]-2.4 \times10^{-3}\left[\left[\mathrm{Pt}\left(\mathrm{H}_{2} \mathrm{O}\right) \mathrm{Cl}_{3}\right]^{-}\right]\left[\mathrm{Cl}^{-}\right]$

where square brackets are used to denote molar concentrations. The equilibrium constant $\mathrm{K}_{\mathrm{c}}=....$. (Nearest integer)

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When one of ampere current flows for $1\,\sec $ through a conductor, this quantity of electricity is known as

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Choose the correct statement($s$) among the following.

$(A)$ $SnCl _2 \cdot 2 H _2 O$ is a reducing agent.

$(B)$ $SnO _2$ reacts with $KOH$ to form $K _2\left[ Sn ( OH )_6\right]$.

$(C)$ A solution of $PbCl _2$ in $HCl$ contains $Pb ^{2+}$ and $Cl ^{-}$ions.

$(D)$ The reaction of $Pb _3 O _4$ with hot dilute nitric acid to give $PbO _2$ is a redoxreaction.

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The $IUPAC$ name of $\begin{matrix}
C{{H}_{2}}-CH=CH-CHO \\
|\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, \\
CHO\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\, \\
\end{matrix}$ is

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