D & f- BLOCK ELEMENTS practice · Hard

Metallic bonds do not play a role in:

A solution when diluted with ${\mathrm{H}_2}\mathrm{O}$ and boiled gives a white ppt. On addition of excess $\mathrm{N}{\mathrm{H}_4}\mathrm{Cl}/\mathrm{N}{\mathrm{H}_4}\mathrm{OH}$, the volume of precipitate decreases due to dissolution leaving behind a white gelatinous precipitate. The precipitate which dissolves in $\mathrm{N}{\mathrm{H}_4}\mathrm{OH}/\mathrm{N}{\mathrm{H}_4}\mathrm{Cl}$ is:

Which of the following compounds is used as the starting material for the preparation of potassium dichromate?

A blue colouration is not obtained when:

Which of the following reagents does not convert copper sulphate to cuprous state?

In the equation,

$4 \mathrm{M}+8 \mathrm{CN}^{-}+2 \mathrm{H}_2 \mathrm{O}+\mathrm{O}_2 \rightarrow 4\left[\mathrm{M}(\mathrm{CN})_2\right]^{-}+4 \mathrm{OH}^{-}$

Identify the metal (M)

In order to oxidise a mixture of one mole of each of $Fe{C_2}{O_4},\,\,F{e_2}{({C_2}{O_4})_3},\,\,FeS{O_4}$ and $F{e_2}{(S{O_4})_3}$ in acidic medium, the number of moles of $KMn{O_4}$ required is

The actinoids exhibit more number of oxidation states in general than the lanthanoids. This is because

Which of the following statements regarding copper salts is not true?

The colour of $_{62}\mathrm{S}{\mathrm{m}^{3 + }}$ is yellow. The expected colour of ${\mathrm{\;}_{66}}\mathrm{D}{\mathrm{y}^{3 + }}$ is

$\mathrm{KMnO}_4$ reacts with $\mathrm{KI}$, in weakly basic medium to form $\mathrm{I}_2$ and $\mathrm{MnO}_2$. When $250 \mathrm{~ml}$ of $0.1 \mathrm{M} \mathrm{~KI}$ solution reacts with $250 \mathrm{~mL}$ of $0.02 \mathrm{~M} \mathrm{~KMnO}_4$ in basic medium, what is the number of moles of $I_2$ formed?

In chromyl chloride test for confirmation of ${Cl}^{-}$ion, a yellow solution is obtained. Acidification of the solution and addition of amyl alcohol and $10 \% {H}_2 {O}_2$ turns organic layer blue indicating formation of chromium pentoxide. The oxidation state of chromium in that is

$\begin{aligned} & \mathrm{I}_{(\mathrm{a q})}^{\Theta}+\mathrm{MnO}_4^{-}(\mathrm{a q}) \xrightarrow{\mathrm{H}^{+}} \mathrm{x}+\mathrm{Mn}_{(\mathrm{a q})}^{+2} \\ & \mathrm{I}_{(\mathrm{a q})}^{\Theta}+\mathrm{MnO}_4^{-}(\mathrm{a q}) \xrightarrow[\text { weakly } \mathrm{OH}^{\Theta}]{\text { neutral }(\text { or })} \mathrm{y}+\mathrm{MnO}_2 \\ & \mathrm{MnO}_{4(\mathrm{a q})}^{-}+\mathrm{Mn}_{(\mathrm{a q})}^{+2} \xrightarrow{\mathrm{ZnSO}_4} \mathrm{z}+4 \mathrm{H}^{+} \end{aligned}$
products $\mathrm{x}, \mathrm{y}$ and $\mathrm{z}$ are respectively

Arrange $\mathrm{C}{\mathrm{e}^{3 + }},\mathrm{\;L}{\mathrm{a}^{3 + }},\mathrm{\;P}{\mathrm{m}^{3 + }}$ and $\mathrm{Y}{\mathrm{b}^{3 + }}$ in increasing order of their ionic radii

Assertion : ${\text{FeC}}{{\text{l}}_3}$ does not affect iodometric titration of ${\text{CuS}}{{\text{O}}_{\text{4}}}$ Solution

Reason : ${\text{FeC}}{{\text{l}}_3}$ is formed.

Pick out the correct statements from the following.

I. Cobalt (III) is more stable in octahedral complexes.

II. Zinc forms coloured ions or complexes.

III. Most of the $d$-block elements and their compounds are ferromagnetic.

IV. Osmium shows (VIII) oxidation state.

V. Cobalt (II) is more stable in octahedral complexes.