Blog Log in Get Started Free

D & F Block Elements MCQs for NEET — Chemistry Questions with Answers

Practice free D & F Block Elements (Chemistry) NEET multiple-choice questions online with instant answers and detailed explanations. No login required.

All Physics Chemistry Botany Zoology

Language English हिंदी

Chapter Difficulty Show only questions I answered incorrectly Clear Register free for difficulty & keyword filters

● ● ● ● ●

The radius of La³⁺ (atomic number of La=57) is 1.06 $\overset{o}{A}$ . Which one of the following given values will be closest to the radius of Lu³⁺ (atomic number of Lu =71)

1.60 $\overset{o}{A}$

1.40 $\overset{o}{A}$

1.96 $\overset{o}{A}$

0.85 $\overset{o}{A}$

You've reached today's free limit of 20 questions. Log in to keep practising for free.

Explanation

The ionic radius of Lu³⁺ is 0.87 $\overset{o}{A}$ , which is very close to the value 0.85 $\overset{o}{A}$ .This decrease in the ionic radius is due to lanthanoid contraction.

● ● ● ● ●

By calculating E^o value of the following reaction,which one of the following reaction are spontaneous.

Given

$E_{C u^{2 +} / C u}^{o} = 0.34 V, E_{Z n^{2 +} / Z n}^{o} = - 0.76 V, E_{A g^{+} / A g}^{o} = 0.80 V . (a) 2 A g + Z n^{2 +} \to 2 A g^{+} + Z n (b) C u + Z n^{2 +} \to Z n + C u^{2 +} (c) Z n + C u^{2 +} \to Z n^{2 +} + C u (d) 2 A g^{+} + C u \to 2 A g + C u^{2 +}$

Only d

Only b

Both c & d

Both a & c

You've reached today's free limit of 20 questions. Log in to keep practising for free.

● ● ● ● ●

Which of the following has maximum number of unpaired electrons?

Fe²⁺

Fe³⁺

Co³⁺

Co²⁺

You've reached today's free limit of 20 questions. Log in to keep practising for free.

Explanation

Fe3+ has the maximum number of unpaired electrons (5 unpaired electrons) among the given options. The electronic configuration of Fe3+ is [Ar] 3d5, where all five 3d electrons are unpaired, aligning their spins parallel due to the strong exchange energy.

● ● ● ● ●

The atomc number of potassium is 19 & that of manganese is 25. Although the colour of MnO₄^- is dark violet yet the K⁺ is colourless.This is due to the fact that

Mn is a transition element; while K⁺ is not

[MnO₄]^- is negatively charged; while K⁺ has a positive charge.

The effective atomic number of Mn in [MnO₄]^- is 26; while for K⁺ , the atomic number s 18

The Mn in a high positive oxidation state allow charge transfer transitions.

You've reached today's free limit of 20 questions. Log in to keep practising for free.

Explanation

In [MnO₄]^-the oxidation state of Mn is +7 (d^o configuration),expected to be colourless but [MnO₄]^-is coloured due to transfer of charge from oxygen to manganese.

● ● ● ● ●

Heating of Ag with dil. HNO₃ give

NO₂

N₂O

N₂O₃

You've reached today's free limit of 20 questions. Log in to keep practising for free.

Explanation

$2 H N O_{3} (d i l .) \to 2 N O + H_{2} O + 3 O 2 A g + 2 H N O_{3} + O \to 2 A g N O_{3} + H_{2} O] \times 3 6 A g + 8 H N O_{3} \to 6 A g N O_{3} + 2 N O + 4 H_{2} O$

● ● ● ● ●

Zinc dissolve in an excess of NaOH, because of the formation of

ZnO

Zn(OH)₂

NaZn(OH)₃

Na₂ZnO₂

You've reached today's free limit of 20 questions. Log in to keep practising for free.

Explanation

It react with NaOH on moderate heating & form soluble Zincate.

$Z n + 2 N a O H \to N a_{2} Z n O_{2} + H_{2}$

● ● ● ● ●

When excess of SnCl₂ is added to HgCl₂, the substance formed is

Hg₂Cl₂

Cl₂

You've reached today's free limit of 20 questions. Log in to keep practising for free.

Explanation

$S n C l_{2} r e d u c e s H g C l_{2} t o H g_{2} C l_{2} a n d f i n a l l y t o H g 2 H g C l_{2} + S n C l_{2} \to H g_{2} C l_{2} (w h i t e p p t) + S n C l_{4} H g_{2} C l_{2} + S n C l_{2} \to 2 H g (b l a c k) + S n C l_{4}$

● ● ● ● ●

The oxidation number is changed in which of the following case

SO₂ gas is passed into $C r_{2} O_{7}^{2 -} / H^{+}$

Aqueous solution of $C r O_{4}^{2 -}$ is acidified

$C r O_{2} C l_{2}$ is dissolved in NaOH

$C r_{2} O_{7}^{2 -}$ solution is made alkaline

You've reached today's free limit of 20 questions. Log in to keep practising for free.

Explanation

$(A) C r_{2} O_{7}^{2 -} + S O_{2} + 2 H^{+} \to 2 C r^{3 +} + 3 S O_{4}^{2 -} + H_{2} O (c h a n g e) + 6 + 4 + 3 + 6 (B) 2 C r_{2} O_{4}^{2 -} + 2 H^{+} \to C r_{2} O_{7}^{2 -} + H_{2} O (N o c h a n g e) + 6 + 6 (C) C r O_{2} C l_{2} + 2 N a O H \to N a C r O_{4} (N o c h a n g e) + 6 + 6 (D) C r_{2} O_{7}^{2 -} + 2 O H^{-} \to 2 C r O_{4}^{2 -} + H_{2} O (N o c h a n g e) + 6 + 6$

● ● ● ● ●

Which of the following elements form stable dinuclear ions

You've reached today's free limit of 20 questions. Log in to keep practising for free.

Explanation

Hg(l) compound contain mercurous ions (Hg-Hg)²⁺ & not Hg⁺.

The two atoms are bonded together using 6s-orbital.

Zn & Cd also form dinuclear ion (Zn-Zn)²⁺ & (Cd-Cd)²⁺ ; however these ions are unstable & have only been detected in melts of Zn/ZnCl₂ &Cd/CdCl₂ respectively.

● ● ● ● ●

A mixture of Mn²⁺ & Zn²⁺ can be separated by using an excess of

NH₄OH

NaOH

H₂SO₄

HNO₃

You've reached today's free limit of 20 questions. Log in to keep practising for free.

Explanation

$M n^{2 +} + 2 N a O H \to M n (O H)_{2} + 2 N a^{+} (p p t) Z n^{2 +} + 2 N a O H \to Z n (O H)_{2} + 2 N a^{+} (p p t) Z n (O H)_{2} + 2 N a O H \to N a_{2} [Z n (O H)_{2}] S o l u b l e c o m p l e x$

Ready to ace NEET?

Free access · No credit card required

Browse All Questions Create Free Account

Frequently Asked Questions

Yes. You can attempt every D & F Block Elements question on this page for free without logging in, and check the correct answer with a detailed explanation instantly.

No account is required to attempt questions and view answers. A free account adds bookmarks, personal notes, and progress tracking.

The bank mixes NEET previous year questions (PYQs) with practice questions, each tagged with its exam appearances where applicable.