All In One ISC Chemistry Class 12>Chapter 8 - d-and f-Block Elements>Chapter Practice>Q 40

EASY

12th ICSE

IMPORTANT

Earn 100

${NbF}_{4}$ is paramagnetic while ${NbX}_{4} (X = Cl, Br, I)$ are diamagnetic, why?

Important Questions on d-and f-Block Elements

EASY

12th ICSE

IMPORTANT

All In One ISC Chemistry Class 12>Chapter 8 - d-and f-Block Elements>Chapter Practice>Q 40

Out of

La (OH)_{3}

and

Lu {(OH)}_{3}

, which is more basic and why?

EASY

12th ICSE

IMPORTANT

All In One ISC Chemistry Class 12>Chapter 8 - d-and f-Block Elements>Chapter Practice>Q 41

Write the steps involved in the preparation of

K_{2} {Cr}_{2} O_{7}

from

{Na}_{2} {CrO}_{4}

.

EASY

12th ICSE

IMPORTANT

All In One ISC Chemistry Class 12>Chapter 8 - d-and f-Block Elements>Chapter Practice>Q 41

Write the steps involves in the preparation of

{KMnO}_{4}

from

K_{2} {MnO}_{4}

.

MEDIUM

12th ICSE

IMPORTANT

All In One ISC Chemistry Class 12>Chapter 8 - d-and f-Block Elements>Chapter Practice>Q 41

What is the effect of lanthanoid contraction on the chemistry of the lanthanoids?

MEDIUM

12th ICSE

IMPORTANT

All In One ISC Chemistry Class 12>Chapter 8 - d-and f-Block Elements>Chapter Practice>Q 42

A blackish-brown coloured solid

A

which is an oxide of manganese, when fused with alkali metal hydroxide and an oxidising agent like

{KNO}_{3}

, produces a dark green coloured compound

B

which on disproportionation in neutral and acidic solution gives a purple coloured compound

C

. Identify

A

,

B

and

C

and write the reaction involved when compound

C

is heated to

513 K

.

EASY

12th ICSE

IMPORTANT

All In One ISC Chemistry Class 12>Chapter 8 - d-and f-Block Elements>Chapter Practice>Q 42

$E^{\circ} (M^{3 +} M^{2 +})$ values for the first series of transition elements are given below:

${E^{\circ}}_{(V)}$	$Ti$	$V$	$Cr$	$Mn$	$Fe$	$Co$
$M^{3 +} M^{2 +}$	$- 0.37$	$- 0.26$	$- 0.41$	$+ 1.57$	$+ 0.77$	$+ 1.97$

Identify the two strongest oxidising agents in the aqueous solutions from the above data.

EASY

12th ICSE

IMPORTANT

All In One ISC Chemistry Class 12>Chapter 8 - d-and f-Block Elements>Chapter Practice>Q 42

Copper (I) ion is not known in aqueous solution. Explain.

EASY

12th ICSE

IMPORTANT

All In One ISC Chemistry Class 12>Chapter 8 - d-and f-Block Elements>Chapter Practice>Q 42

In this series the highest oxidation state of a metal is exhibited in its oxide. Identify the metal.