The maximum number of bromine atoms present in the final product $P$ upon complete bromination is

Which catalyst is most commonly used in the catalytic reduction of hydrocarbons?

What is $Z$ in the following reaction sequence ?
$C_3H_6$ $\xrightarrow[CCl_4]{Br_2} \underset{\text{(colourless)}}{X}$ $\xrightarrow[\text{(ii) } NaNH_2, \Delta]{\text{(i) } KOH / \text{alcohol}} Y$ $\xrightarrow[\substack{Hg^{2+}, H^{+} \\ 333 \ K}]{H_2O} Z$

$1, 2-$dibromocyclooctane $\xrightarrow[\substack{\text{(ii) } NaNH_2 \\ \text{(iii) } Hg^{2+} / H^{+} \\ \text{(iv) } Zn-Hg / H^{+}}]{\text{(i) } KOH \text{ (alc.) }} \underset{\text{(Major product)}}{P}$. $P$ is

The enolic form of acetone contains

The dibromo compound $[P]$ (molecular formula : $C_{9}H_{10}Br_{2}$) when heated with excess sodamide followed by treatment with dilute $HCl$ gives $[Q]$. On warming $[Q]$ with mercuric sulphate and dilute sulphuric acid yields $[R]$ which gives positive Iodoform test but negative Tollen's test. The compound $[P]$ is: