d- and f-Block Elements

In the chemical reaction between stoichiometric quantities of $\ce{KMnO4}$ and KI in weakly basic solution, what is the number of moles of $\ce{I2}$ released for 4 moles of $\ce{KMnO4}$ consumed?

An acidified solution of potassium chromate was layered with an equal volume of amyl alcohol. When it was shaken after the addition of 1 mL of 3% $\ce{H2O2}$, a blue alcohol layer was obtained. The blue color is due to the formation of a chromium (VI) compound 'X'. What is the number of oxygen atoms bonded to chromium through only single bonds in a molecule of X?

Fusion of $\ce{MnO2}$ with KOH in presence of $\ce{O2}$ produces a salt W. Alkaline solution of W upon electrolytic oxidation yields another salt X. The manganese containing ions present in W and X, respectively, are Y and Z. Correct statement(s) is(are)

Consider the following reactions (unbalanced)

$\ce{Zn}$ + hot conc. $\ce{H2SO4} \to$ G + R + X

$\ce{Zn}$ + conc. $\ce{NaOH} \to$ T + Q

G + $\ce{H2S}$ + $\ce{NH4OH} \to$ Z (a precipitate) + X + Y

Choose the correct option(s)

Among the species given below, the total number of diamagnetic species is ______.

H atom, $\ce{NO2}$ monomer, $\ce{O2-}$ (superoxide), dimeric sulphur in vapour phase, $\ce{Mn3O4}$, $\ce{(NH4)2[FeCl4]}$, $\ce{(NH4)2[NiCl4]}$, $\ce{K2MnO4}$, $\ce{K2CrO4}$

To measure the quantity of $\mathrm{MnCl_2}$ dissolved in an aqueous solution, it was completely converted to $\mathrm{KMnO_4}$ using the reaction,

$$\mathrm{MnCl_2 + K_2S_2O_8 + H_2O \rightarrow KMnO_4 + H_2SO_4 + HCl} \quad \text{(equation not balanced)}.$$

Few drops of concentrated HCl were added to this solution and gently warmed. Further, oxalic acid (225 mg) was added in portions till the colour of the permanganate ion disappeared. The quantity of $\mathrm{MnCl_2}$ (in mg) present in the initial solution is ____.

(Atomic weights in g mol$^{-1}$: Mn = 55, Cl = 35.5)

Which of the following combination will produce $\ce{H2}$ gas?

The option(s) with only amphoteric oxides is(are)

In the following reactions, ZnO is respectively acting as a/an :

(a) $\ce{ZnO + Na2O -> Na2ZnO2}$

(b) $\ce{ZnO + CO2 -> ZnCO3}$

The pair of compounds having metals in their highest oxidation state is :

Which of the following ions does not liberate hydrogen gas on reaction with dilute acids ?

In neutral or faintly alkaline solution, 8 moles of permanganate anion quantitatively oxidize thiosulphate anions to produce X moles of a sulphur containing product. The magnitude of X is

Which of the following compounds is metallic and ferromagnetic ?

Which one of the following species is stable in aqueous solution ?

The transition metal ions responsible for color in ruby and emerald are, respectively :

The correct statement(s) about $\ce{Cr^{2+}}$ and $\ce{Mn^{3+}}$ is(are)

[Atomic numbers of Cr = 24 and Mn = 25]

The color of $\ce{KMnO4}$ is due to :

Which of the following statements is false ?

Which series of reactions correctly represents chemical relations related to iron and its compound ?

Chloro compound of Vanadium has only spin magnetic moment of 1.73 BM. This Vanadium chloride has the formula : (at. no. of V = 23)