Which of the following reactions is S_ N_1 type?

$\mathrm{CH}_{3}-\mathrm{CH}=\mathrm{CH}_{2}$ $\xrightarrow[{{\text{H}}_{2}}{{\text{O}}_{2}},\bar{O}\text{H}]{\text{B}{{\text{H}}_{3}},\text{THF}}(P)$ $\xrightarrow[\text{C}{{\text{H}}_{2}}\text{C}{{\text{l}}_{2}}]{\text{ Pyridinium Chloro Chromate }(\text{PCC})}$ $(Q)$

$\mathrm{CH}_{3}-\mathrm{CH}=\mathrm{CH}_{2}$ $\xrightarrow[NaB{{H}_{4}}\,,\,H{{O}^{\Theta }}]{Hg\,{{(OAc)}_{2}}\,,\,{{H}_{2}}O}(R)$ $\xrightarrow[\text{C}{{\text{H}}_{2}}\text{C}{{\text{l}}_{2}}]{\text{ Pyridinium Chloro Chromate }(\text{PCC})}$ $(S)$

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Number of ambidentate ligands among the following is ................ $\mathrm{NO}_2^{-}, \mathrm{SCN}^{-}, \mathrm{C}_2 \mathrm{O}_4^{2-}, \mathrm{NH}_3, \mathrm{CN}^{-}, \mathrm{SO}_4^{2-}, \mathrm{H}_2 \mathrm{O}$.

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Which of the following statement($s$) is(are) true ?

$(1)$ Oxidation of glucose with bromine water gives glutamic acid

$(2)$ The two six-membered cyclic hemiacetal forms of $D-(+)$-glucose ard called anomers

$(3)$ Hydrolysis of sucrose gives dextrorotatory glucose and laevorotatory fructose

$(4)$ Monosaccharides cannot be hydrolysed to give polyhydroxy aldehydes and ketones

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Cinnabar is an ore of:

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Which of the following is planar