D & f- BLOCK ELEMENTS practice · Mixed difficulty

Which product is obtained during reaction of ${MnO}_4^{-}$with ${I}^{-}$in faintly alkaline condition?

In the following salts the lowest value of magnetic moment is observed in

In which of the following reactions, reaction of silver with the given acids lead to the formation of
compound & silver, along with liberation of gas ?

$\mathrm{V}_2 \mathrm{O}_5$ reacts with alkalies to give

In chromite ore, the oxidation number of iron and chromium are respectively.

Which of the following statements are correct?

(i) Chromium has the highest melting point among the series 1 metals.

(ii) Number of unpaired electrons is greater in Cr than other elements of series 1 .

(iii) In any row the melting point of transition metal increases as the atomic number increases.

Among the following the compound that is both paramagnetic and coloured is

Steel resistant to acid is:

A transition metal $\mathrm{M}$ can exist in two oxidation states +1 and +2 . It forms a sulphide whose experimental formula is given by $\mathrm{M}_{\mathrm{x}} \mathrm{S}$ where $2 > x > 1$. Then the ratio of metal ion in +1 state to those in +2 state in sulphide is given by

Which of the following statements are correct?

(A) The $\mathrm{M}^{3+} / \mathrm{M}^{2+}$ reduction potential for iron is greater than manganese.

(B) The higher oxidation states of first row $d$-block elements get stabilized by oxide ion

(C) Aqueous solution of $\mathrm{Cr}^{2+}$ can liberate hydrogen from dilute acid

(D) Magnetic moment of $\mathrm{V}^{2+}$ is observed between $4.4-5.2 \mathrm{BM}$

Choose the correct answer from the options given below:

The metal ion whose electronic configuration is
not affected by the nature of the ligand and which
gives a violet colour in non-luminous flame under
hot condition in borax bead test is

The highest magnetic moment is shown by the transition metal ion with the configuration

The formula of azurite is

Statement I : Generally transition elements exhibit higher enthalpies of atomisation.

Statement II : $\mathrm{Cr}^{2+}$ is reducing while $\mathrm{Mn}^{3+}$ is oxidizing.

In the light of above statements, choose the correct option among the following.

Assertion(A) Mn-atom loses $n s$ electrons first during ionisation as compared to $(n-1) d$ electrons.

Reason(R) The effective nuclear charge experienced by $(n-1) d$ electrons is greater than that by $n s$ electrons.

Catalyst used in oxo-process is

Highest oxidation state exhibited by an actinoid is

For making good quality mirrors, plates of float glasses are used. These are obtained by floating molten glass over a liquid metal which does not solidify before glass. The metal can be:

Which of the following compounds has colour but no unpaired electrons?

Assertion: Out of $CrO_3 \,\&\, Al_2O_3, CrO_3$ having lower melting point than $Al_2O_3$.
Reason: Oxidation state of $Cr$ in $CrO_3$ is high

Formation of coloured solution is possible when metal ion in the compound contains

The pair that has similar atomic radii is

The incorrect statement(s) among (1)-(3) is (are)
1) W(VI) is more stable than Cr(VI).
2) In the presence of HCl, permanganate titrations provide satisfactory results.
3) Some lanthanoid oxides can be used as phosphors.

Which of the following is not a member of $3d$-transition series?

The correct statement are

Magnetite is:

Blue vitriol is:

The oxidation number of Mn in the product of alkaline oxidative fusion of $\mathrm{Mn}{\mathrm{O}_2}$ is

An acid radical (A) when treated with dil. $\mathrm{H}_2 \mathrm{SO}_4$, a colourless gas (B) comes out which is suffocating with the smell of burning sulphur. Gas B when treated with $\mathrm{K}_2 \mathrm{Cr}_2 \mathrm{O}_7$ acidified with dil. $\mathrm{H}_2 \mathrm{SO}_4$, green colour appeared. $\mathrm{A}$ and $\mathrm{B}$ are respectively

The transition element that has lowest enthalpy of atomization is: