Unclassified (chemistry)

The reaction of $\mathrm{K}_3\left[\mathrm{Fe}(\mathrm{CN})_6\right]$ with freshly prepared $\mathrm{FeSO}_4$ solution produces a dark blue precipitate called Turnbull's blue. Reaction of $\mathrm{K}_4\left[\mathrm{Fe}(\mathrm{CN})_6\right]$ with the $\mathrm{FeSO}_4$ solution in complete absence of air produces a white precipitate $\mathbf{X}$, which turns blue in air. Mixing the $\mathrm{FeSO}_4$ solution with $\mathrm{NaNO}_3$, followed by a slow addition of concentrated $\mathrm{H}_2 \mathrm{SO}_4$ through the side of the test tube produces a brown ring. Precipitate $\mathbf{X}$ is

Match the compounds in LIST-I with the observations in LIST-II, and choose the correct option. LIST-I (I) Aniline (II) $o$-Cresol (III) Cysteine (IV) Caprolactam LIST-II (P) Sodium fusion extract of the compound on boiling with $\mathrm{FeSO}_{4}$, followed by acidification with conc. $\mathrm{H}_{2} \mathrm{SO}_{4}$, gives Prussian blue color. (Q) Sodium fusion extract of the compound on treatment with sodium nitroprusside gives blood red color. (R) Addition of the compound to a saturated solution of $\mathrm{NaHCO}_{3}$ results in effervescence. (S) The compound reacts with bromine water to give a white precipitate. (T) Treating the compound with neutral $\mathrm{FeCl}_{3}$ solution produces violet color.

Among $[\mathrm{Ni(CO)}_{4}]$, $[\mathrm{NiCl}_{4}]^{2-}$, $[\mathrm{Co(NH_3)_{4}Cl_2}]\mathrm{Cl}$, $\mathrm{Na_3}[\mathrm{CoF_6}]$, $\mathrm{Na_2O_2}$ and $\mathrm{CsO_2}$ number of paramagnetic compounds is

LIST-I contains compounds and LIST-II contains reactions LIST-I (I) $\mathrm{H}_2 \mathrm{O}_2$ (II) $\mathrm{Mg}(\mathrm{OH})_2$ (III) $\mathrm{BaCl}_2$ (IV) $\mathrm{CaCO}_3$ LIST-II (P) $\mathrm{Mg}\left(\mathrm{HCO}_{3}\right)_{2}+\mathrm{Ca}(\mathrm{OH})_{2} \rightarrow$ (Q) $\mathrm{BaO}_{2}+\mathrm{H}_{2} \mathrm{SO}_{4} \rightarrow$ (R) $\mathrm{Ca}(\mathrm{OH})_{2}+\mathrm{MgCl}_{2} \rightarrow$ (S) $\mathrm{BaO}_{2}+\mathrm{HCl} \rightarrow$ (T) $\mathrm{Ca}\left(\mathrm{HCO}_{3}\right)_{2}+\mathrm{Ca}(\mathrm{OH})_{2} \rightarrow$ Match each compound in LIST-I with its formation reaction(s) in LIST-II, and choose the correct option\

The green colour produced in the borax bead test of a chromium(III) salt is due to

The reaction of $\mathrm{HClO}_{3}$ with $\mathrm{HCl}$ gives a paramagnetic gas, which upon reaction with $\mathrm{O}_{3}$ produces

Calamine, malachite, magnetite and cryolite, respectively, are

Which of the following liberates $\mathrm{O}_{2}$ upon hydrolysis?

The reaction of $\mathrm{Pb}\left(\mathrm{NO}_{3}\right)_{2}$ and $\mathrm{NaCl}$ in water produces a precipitate that dissolves upon the addition of $\mathrm{HCl}$ of appropriate concentration. The dissolution of the precipitate is due to the formation of

On decreasing the $p \mathrm{H}$ from 7 to 2, the solubility of a sparingly soluble salt (MX) of a weak acid (HX) increased from $10^{-4} \mathrm{~mol} \mathrm{~L}^{-1}$ to $10^{-3} \mathrm{~mol} \mathrm{~L}^{-1}$. The $p\mathrm{~K}_{\mathrm{a}}$ of $\mathrm{HX}$ is