Question Set A

Tamilnadu 12th Standard Chemistry Solid State Important Questions Study Material - QB365

Download Tamil Nadu 12th Standard Chemistry question papers, model tests, one-mark questions, important questions, and public exam papers in PDF format. Free study materials and answer keys for TN State Board students.

Questions:

Multiple Choice Question

50 x 1 = 50

Among the transition metals of 3d series, the one that has highest negative \(\left( \frac { M^{ 2+ } }{ M } \right) \) standard electrode potential is _______.

(a)

(b)

(c)

(d)

Which one of the following ions has the same number of unpaired electrons as present in V³⁺?

(a)

Ti³⁺

(b)

Fe³⁺

(c)

Ni²⁺

(d)

Cr³⁺

The magnetic moment of Mn²⁺ ion is _______.

(a)

5.92BM

(b)

2.80BM

(c)

8.95BM

(d)

3.90BM

Which of the following statements is not true?

(a)

on passing H₂S, through acidified K₂Cr₂O₇ solution, a milky colour is observed

(b)

Na₂Cr₂O₇ is preferred over K₂Cr₂O₇ in volumetric analysis

(c)

K₂Cr₂O₇ solution in acidic medium is orange in colour

(d)

K₂Cr₂O₇ solution becomes yellow on increasing the P^H beyond 7

How many moles of I₂ are liberated when 1 mole of potassium dichromate react with potassium iodide?

(a)

(b)

(c)

(d)

The number of moles of acidified KMnO₄required to oxidize 1 mole of ferrous oxalate(FeC₂O₄) is _______.

(a)

(b)

(c)

0.6

(d)

1.5

Which one of the following statements related to lanthanons is incorrect?

(a)

Europium shows +2 oxidation state

(b)

The basicity decreases as the ionic radius decreases from Pr to Lu.

(c)

All the lanthanons are much more reactive than aluminium

(d)

Ce⁴⁺ solutions are widely used as oxidising agents in volumetric analysis.

Which of the following lanthanoid ions is diamagnetic?

(a)

Eu²⁺

(b)

Yb²⁺

(c)

Ce²⁺

(d)

Sm²⁺

Which of the following oxidation states is most common among the lanthanoids?

(a)

(b)

(c)

(d)

10.

The most common oxidation state of actinoids is _______.

(a)

(b)

(c)

(d)

11.

The actinoid elements which show the highest oxidation state of +7 are _______.

(a)

Np, Pu, Am

(b)

U, Fm, Th

(c)

U, Th, Md

(d)

Es, No, Lr

12.

Which one of the following is not correct?

(a)

La(OH)₃ is less basic than Lu(OH)₃

(b)

In lanthanoid series ionic radius of Ln³⁺ ions decreases

(c)

La is actually an element of transition metal series rather than lanthanide series

(d)

Atomic radii of Zr and Hf are same because of lanthanide contract

13.

An ionic compound A_x B_y crystallizes in fcc type crystal structure with B ions at the centre of each face and A ion occupying corners of the cube the correct formula of A_x,B_y is ________.

(a)

(b)

AB₃

(c)

A₃B

(d)

A₈B₆

14.

The ratio of close packed atoms to tetrahedral hole in cubic packing is ________.

(a)

1:1

(b)

1:2

(c)

2:1

(d)

1:4

15.

In calcium fluoride, having the fluorite structure the coordination number of Ca²⁺ ion and F^- Ion are ________.

(a)

4 and 2

(b)

6 and 6

(c)

8 and 4

(d)

4 and 8

16.

In a solid atom M occupies ccp lattice and \(\left( \frac { 1 }{ 3 } \right) \) of tetrahedral voids are occupied by atom N. Find the formula of solid formed by M and N ________.

(a)

(b)

M₃N

(c)

MN₃

(d)

M₃N₂

17.

The ionic radii of A⁺ and B⁻ are 0.98 x 10^-10 m and 1.81 x 10^-10m. the coordination number of each ion in AB is ________.

(a)

(b)

(c)

(d)

18.

For a first order reaction A ⟶ B the rate constant is x min⁻¹. If the initial concentration of A is 0.01M, the concentration of A after one hour is given by the expression.

(a)

001. e^−x

(b)

1 x 10^-2(1-e^-60x)

(c)

(1 x 10^-2)e^-60x

(d)

none of these

19.

A zero order reaction X ⟶ Product, with an initial concentration 0.02M has a half life of 10 min. if one starts with concentration 0.04M, then the half life is

(a)

10 s

(b)

5 min

(c)

20 min

(d)

cannot be predicted using the given information

20.

Among the following graphs showing variation of rate constant with temperature (T) for a reaction, the one that exhibits Arrhenius behavior over the entire temperature range is _______.

(a)

(b)

(c)

(d)

both (b) and (c)

21.

For a first order reaction A ⟶ product with initial concentration x mol L^-1, has a half life period of 2.5 hours. For the same reaction with initial concentration \(\left( \frac { x }{ 2 } \right) \) mol L^-1 the half life is

(a)

(2.5 x 2) hours

(b)

\(\left( \frac { 2.5 }{ 2 } \right) \) hours

(c)

2.5 hours

(d)

Without knowing the rate constant, t_1/2 cannot be determined from the given data

22.

The radius of an atom is 300pm, if it crystallizes in a face centered cubic lattice, the length of the edge of the unit cell is ________.

(a)

488.5pm

(b)

848.5pm

(c)

884.5pm

(d)

484.5pm

23.

The fraction of total volume occupied by the atoms in a simple cubic is ________.

(a)

\(\left( \frac { \pi }{ 4\sqrt { 2 } } \right) \)

(b)

\(\left( \frac { \pi }{ 6 } \right) \)

(c)

\(\left( \frac { \pi }{ 4 } \right) \)

(d)

\(\left( \frac { \pi }{ 3\sqrt { 2 } } \right) \)

24.

The yellow colour in NaCl crystal is due to ________.

(a)

excitation of electrons in F centers

(b)

reflection of light from Cl^- ion on the surface

(c)

refraction of light from Na⁺ ion

(d)

all of the above

25.

If ‘a’ stands for the edge length of the cubic system sc, bcc, and fcc. Then the ratio of radii of spheres in these systems will be respectively ________.

(a)

\(\left( \frac { 1 }{ 2 } a;\frac { \sqrt { 3 } }{ 2 } a;\frac { \sqrt { 2 } }{ 2 } a \right) \)

(b)

\(\left( \sqrt { 1a } :\sqrt { 3a } :\sqrt { 2a } \right) \)

(c)

\(\left( \frac { 1 }{ 2 } a:\frac { \sqrt { 3 } }{ 4 } a:\frac { 1 }{ 2\sqrt { 2 } } a \right) \)

(d)

\(\frac { 1 }{ 2 } a:\sqrt { 3 } a:\frac { 1 }{ \sqrt { 2 } } a\)

26.

If ‘a’ is the length of the side of the cube, the distance between the body centered atom and one corner atom in the cube will be_________.

(a)

\(\left( \cfrac { 2 }{ \sqrt { 3 } } \right) a\)

(b)

\(\left( \cfrac { 4 }{ \sqrt { 3 } } \right) a\)

(c)

\(\left( \cfrac { \sqrt { 3 } }{ 4 } \right) a\)

(d)

\(\left( \cfrac { \sqrt { 3 } }{ 2 } \right) a\)

27.

Schottky defect in a crystal is observed when ______.

(a)

unequal number of anions and anions are missing from the lattice

(b)

Equal number of cations and anions are missing from the lattice

(c)

an ion leaves its normal site and occupies an interstitial site

(d)

no ion is missing from its lattice

28.

The crystal with a metal deficiency defect is ________.

(a)

NaCl

(b)

FeO

(c)

ZnO

(d)

KCl

29.

A two dimensional solid pattern formed by two different atoms X and Y is shown below. The black and white squares represent atoms X and Y respectively. The simplest formula for the compound based on the unit cell from the pattern is _______.

(a)

XY₈

(b)

X₄Y₉

(c)

XY₂

(d)

XY₄

30.

The decomposition of phosphine (PH₃) on tungsten at low pressure is a first order reaction. It is because the _____.

(a)

rate is proportional to the surface coverage

(b)

rate is inversely proportional to the surface coverage

(c)

rate is independent of the surface coverage

(d)

rate of decomposition is slow

31.

The addition of a catalyst during a chemical reaction alters which of the following quantities?

(a)

Enthalpy

(b)

Activation energy

(c)

Entropy

(d)

Internal energy

32.

Consider the following statements:
(i) increase in concentration of the reactant increases the rate of a zero order reaction.
(ii) rate constant k is equal to collision frequency A if E_a = 0
(iii) rate constant k is equal to collision frequency A if E_a = ∞
(iv) a plot of ln (k) vs T is a straight line.
(v) a plot of ln (k) vs \(\left( \frac { 1 }{ T } \right) \) is a straight line with a positive slope.
Correct statements are

(a)

(ii) only

(b)

(ii) and (iv)

(c)

(ii) and (v)

(d)

(i), (ii) and (v)

33.

What is the activation energy for a reaction if its rate doubles when the temperature is raised from 200K to 400K? (R = 8.314 JK^-1 mol^-1)

(a)

234.65 kJ mol^-1

(b)

434.65 kJ mol^-1

(c)

2.305 kJ mol^-1

(d)

334.65 J mol^-1

34.

For a first order reaction, the rate constant is 6.909 min^-1the time taken for 75% conversion in minutes is _______.

(a)

\(\left( \frac { 3 }{ 2 } \right) { \log 2 }\)

(b)

\(\left( \frac { 2 }{ 3 } \right) \log2\)

(c)

\(\left( \frac { 3 }{ 2 } \right) \log\left( \frac { 3 }{ 4 } \right) \)

(d)

\(\left( \frac { 2 }{ 3 } \right) \log\left( \frac { 4 }{ 3 } \right) \)

35.

The rate constant of a reaction is 5.8 x 10^-2 S^-1 The order of the reaction is ______.

(a)

First order

(b)

zero order

(c)

Second order

(d)

Third order

36.

If the initial concentration of the reactant is doubled, the time for half reaction is also doubled. Then the order of the reaction is______.

(a)

Zero

(b)

one

(c)

Fraction

(d)

none

37.

If 75% of a first order reaction was completed in 60 minutes, 50% of the same reaction under the same conditions would be completed in_______.

(a)

20 minutes

(b)

30 minutes

(c)

35 minutes

(d)

75 minutes

38.

The correct difference between first and second order reactions is that________.

(a)

A first order reaction can be catalysed; a second order reaction cannot be catalysed.

(b)

The half life of a first order reaction does not depend on [A₀]; the half life of a second order reaction does depend on [A₀].

(c)

The rate of a first order reaction does not depend on reactant concentrations; the rate of a second order reaction does depend on reactant concentrations.

(d)

The rate of a first order reaction does depend on reactant concentrations; the rate of a second order reaction does not depend on reactant concentrations.

39.

This reaction follows first order kinetics. The rate constant at particular temperature is 2.303 x 10^-2 hour^-1. The initial concentration of cyclopropane is 0.25 M. What will be the concentration of cyclopropane after 1806 minutes? (log 2 = 0.3010)

(a)

0.125 M

(b)

0.215 M

(c)

0.25 x 2.303 M

(d)

0.05 M

40.

The method by which aniline cannot be prepared is _________.

(a)

degradation of benzamide with Br₂ / NaOH

(b)

potassium salt of phthalimide treated with chlorobenzene followed by hydrolysis with aqueous NaOH solution.

(c)

reduction of Nitrobenzene with LiAlH₄

(d)

reduction of nitrobenzene by Sn / HCl

41.

Which one of the following will not undergo Hofmann bromamide reaction.

(a)

CH₃CONHCH₃

(b)

CH₃CH₂CONH₂

(c)

CH₃CONH₂

(d)

C₆H₅CONH₂

42.

CH₃CH₂ Br \(\overset { aqNaOH }{ \underset { \Delta }{ \longrightarrow } } A\overset { { KMnO }_{ 4 }{ /H }^{ + } }{ \underset { \Delta }{ \longrightarrow } } B\overset { { NH }_{ 3 } }{ \underset { \Delta }{ \longrightarrow } } C\overset { { Br }_{ 2 }/NaOH }{ \longrightarrow } D\) D' is________.

(a)

bromomethane

(b)

α - bromo sodium acetate

(c)

methanamine

(d)

acetamide

43.

Aniline + benzoylchloride \(\overset { NaOH }{ \longrightarrow } \)C₆H₅ - NH - COC₆ H₅ this reaction is known as ______.

(a)

Friedel – crafts reaction

(b)

HVZ reaction

(c)

Schotten – Baumann reaction

(d)

none of these

44.

The product formed by the reaction an aldehyde with a primary amine ________.

(a)

carboxylic acid

(b)

aromatic acid

(c)

schiff ’s base

(d)

ketone

45.

Which of the following reaction is not correct.

(a)

CH₃ CH₂ NH₂ \(\overset { { HNO }_{ 2 } }{ \longrightarrow } \)CH₃CH₂ OH + N₂

(b)

(c)

CH₂ CONH₂ \(\overset { { Br }_{ 2 }/NaOH }{ \longrightarrow } \)CH₃ NH₂

(d)

none of these

46.

When aniline reacts with acetic anhydride the product formed is_______.

(a)

o – aminoacetophenone

(b)

m-aminoacetophenone

(c)

p – aminoacetophenone

(d)

acetanilide

47.

Secondary nitro alkanes react with nitrous acid to form _______.

(a)

red solution

(b)

blue solution

(c)

green solution

(d)

yellow solution

48.

Which one of the following is most basic?

(a)

2,4 – dichloroaniline

(b)

2,4 – dimethyl aniline

(c)

2,4 – dinitroaniline

(d)

2,4 – dibromoaniline

49.

IUPAC name for the amine

(a)

3 – Bimethylamino – 3 – methyl pentane

(b)

3 (N,N – Triethyl) – 3- amino pentane

(c)

3 – N,N – trimethyl pentanamine

(d)

N,N – dimethyl – 3- methyl - pentan - 3 amine

50.

Ammonium salt of benzoic acid is heated strongly with and the product so formed is reduced and then treated with NaNO₂ / HCl at low temperature. The final compound formed is _______.

(a)

Benzene diazonium chloride

(b)

Benzyl alcohol

(c)

Phenol

(d)

Nitrosobenzene

Visit QB365-SLMS - https://www.qb365.in/slms/

Answers Key:

Multiple Choice Question

50 x 1 = 50

(a)
Ti

Mn²⁺ ⇒ 3d⁵ contains 5 unpaired electrons
n = 5,
\( \sqrt{n(n+ 2)} \) BM
\(= \sqrt{5(5+ 2)} = \sqrt{35} = 5.92 BM\)

(b)
Na₂Cr₂O₇ is preferred over K₂Cr₂O₇ in volumetric analysis

+7 +2+3 2+ 3+ 4+
MnO₄^- + FeC₂O₄ ⟶ Mn²⁺ + Fe³⁺ + 2CO₂
5e^-acception 3e^- release
5 moles of FeC₂O₄ \(\equiv\) 3 moles of KMnO₄
1 mole of FeC₂O₄ \(\equiv\) (3/5) moles of KMnO₄
1 mole of FeC₂O₄ \(\equiv\) 0.6 moles of KMnO₄

As we move from La to Lu, their metallic behaviour because almost similar to that of aluminium.

Yb²⁺ - 4f¹⁴ - no unpaired electrons - diamagnetic

(d)
+3

10.

(b)
+3

11.

(a)
Np, Pu, Am

12.

(a)
La(OH)₃ is less basic than Lu(OH)₃

13.

Number of A ions = N_c/8 = 8/8 = 1
Number of B ions = N_f/2 = 6/2 = 3
Simplest formula = AB₃

14.

If number of close packed atoms = N, then
The number of Tetrahedral holes formed = 2N
The number of Octahedral holes formed = N
Therefore, N:2N = 1:2

15.

16.

If the total number of M atoms is n, then the number of tetrahedral voids = 2n
Given that \(\left( \frac { 1 }{ 3 } \right) ^{rd}\) of tetrahedral voids are occupied.
i.,e \(\left( \frac { 1 }{ 3 } \right) \times 2n\) are occupied by N atoms
\(\therefore\)M : N = n : \(\left( \frac { 2 }{ 3 } \right) n\)
= 1 : \(\frac { 2 }{ 3 }\)
Hence M₃N₂ = 3 : 2

17.

\(\left( \frac { r_{c^+} }{ r_{A^-} } \right) \) = \(\left( \frac { 0.98 \times 10^{-10 }}{ 1.81 \times 10^{-10} } \right) = 0.54\)
It is in the range of 0.414 to 0.732, hence the coordination number of each ion is 6.

18.

\(k=\frac { 2.303 }{ t } log\frac { \left[ { A }_{ 0 } \right] }{ \left[ A \right] } \)
\(k=\frac { 1 }{ t } ln \frac { \left[ { A }_{ 0 } \right] }{ \left[ A \right] } \)
\(e^{kt}=\frac { \left[ { A }_{ 0 } \right] }{ \left[ A \right] }\)
[A] = [A₀] e^kt
In this case
k = x min^-1 and [A₀] = 0.01 M = 1 x 10^-2M
t = 1 hour = 60 min
[A] = (1 x 10^-2)e^-60x

19.

for n ≠ 1 t_1/2 = \(\frac{2^{n-1} -1}{(n- 1) k[A_{0}]^{-1}}\)
for n = 0; t_1/2 = \(\frac{1}{2 k[A_{0}]^{-1}}\)
t_1/2 = \(\frac{[A_{0}]}{2 k}\)
t_1/2 α [A₀] ...(1)
Given [A₀] = 0.002 M; t_1/2 = 10 min
[A₀] = 0.04M; t_1/2 = ?
Substitute in (1)
10 min α 0.02 M...(2)
t_1/2 α 0.04M ....(3)
(3)(2)
⇒ t_1/2 / 10 min
= 0.04 M/0.02 M
t_1/2 = 2 x 10 min = 20 min

20.

\(k=A{ e }^{ -\left( \frac { { E }_{ a } }{ RT } \right) }\)
In k = In A - \({ \left( \frac { { E }_{ a } }{ R } \right) }\) \(\left( \frac { 1 }{ T } \right) \)
This equation is of the form of a straight line y = mx+c
A plot of In k Vs \(\left( \frac { 1 }{ T } \right) \) gives a straight line with a negative slope.

21.

For a first order reaction
t_1/2 = \(\frac { 0.693 }{ { k }}\)
t_1/2 does not depend on the initial concentration and it remains constant (whatever may be the initial concentration)
t_1/2 = 2.5 hrs

22.

let edge length = a
\(\sqrt{2a} = 4r\)
\(a = \frac{4 \times 300}{\sqrt {2}}\)
a = 600 x 1.414
a = 848.4 pm

23.

(b)
\(\left( \frac { \pi }{ 6 } \right) \)

24.

(a)
excitation of electrons in F centers

25.

sc ⇒ 2r = a
⇒ r = a/2
bcc ⇒ 4r = \( \sqrt{3a} \) ⇒ r = \(\frac { \sqrt{3a}} {4}\)
fcc ⇒ 4r ⇒ \( \sqrt{2a} \) ⇒ r = \(\frac { \sqrt{2a}} {4} = \frac { a} {2\sqrt{2a}}\)
\(\left( \frac { a }{ 2 } :\frac { \sqrt { 3 } }{ 4 } a:\frac { a }{ 2\sqrt { 2 } } \right) \)

26.

If a is the length of the side, then the length of the leading diagonal passing through the body centered atom is \(\sqrt{3a} \)
Required distance = \(\left( \cfrac { \sqrt { 3 } }{ 2 } \right) a\)

27.

(b)
Equal number of cations and anions are missing from the lattice

28.

(b)
FeO

29.

(a)
XY₈

30.

Given:
At low pressure the reaction follows first order therefore,
Rate α [reactant]¹
Rate α (surface area)
At high pressure due to the complete coverage of surface area, the reaction follows zero order.
Rate α [reactant]⁰
Therefore the rate is independent of surface area.

31.

A catalyst provides a new path to the reaction with low activation energy. i.e., it lowers the activation energy.

32.

(rate constant K is equal to collision frequency A if E_a = 0)
In zero order reactions, increase in the concentration of reactant does not alter the rate.
So statement (i) is wrong.
\(k=A{ e }^{ -\left( \frac { { E }_{ a } }{ RT } \right) }\)
if E_a = 0 so, statement (ii) is correct, and statement (iii) is wrong
k = Ae⁰
k = A
In k = In A - \({ \left( \frac { { E }_{ a } }{ R } \right) }\) \(\left( \frac { 1 }{ T } \right) \)
This equation is of the form of a straight line y = mx+c
A plot of In k Vs \(\left( \frac { 1 }{ T } \right) \) gives a straight line with a negative slope
So statement (iv) and (v) are wrong.

33.

T₁= 200 K ; k = k₁
T₂ =400 K ; k₁= k₂= 2k₁
log\(\frac {{ k }_{ 2 } }{ { k }_{ 1 } } =\frac { { E }_{ a } }{ 2.303R } \left[ \frac { { T }_{ 2 }-{ T }_{ 1 } }{ { T }_{ 1 }{ T }_{ 2 } } \right] \)
log \( [\frac {{2 k }_{ 1 } }{ { k }_{ 1 } }]\)
\(= \left[ \frac { E_{a} }{ 2.303\times 8.314 JK^{-1} mol^{-1} } \right] \)
\(= \left[ \frac { 400 k - 200K }{200 k \times 400 k } \right] \)
\(E_{a} = \frac{ 0.3010 \times 2.303 \times 8.314 JK^{-1}mol^{-1} \times 200K \times 400 K}{200 K}\)
E_a = 2305 J mol^-1
E_a = 2.305 kJ mol^-1

34.

\(k=\frac { 2.303 }{ t } \log\frac { \left[ { A }_{ 0 } \right] }{ \left[ A \right] } \)
[A₀] = 100: [A] = 25
\(6.909=\frac { 2.303 }{ t } \log\frac { \left[ {100 } \right] }{ \left[ 25\right] } \)
\(t =\frac { 2.303 }{ 6.909 } \log(4)\)
\(t =\frac { 1 }{ 3 } \log(2^2)\)
\(= \left( \frac { 2 }{ 3 } \right) \log2\)

35.

(a)
First order

36.

t_1/2 α \(\frac{1}{[A_{0}]^{n-1}}\)...(1)
If [A₀ = 2[A₀]; then t_1/2 = 2t_1/2
2t_1/2 α \(\frac{1}{[2A_{0}]^{n-1}}\)...(2)
(2)/(1) = \(2= \frac{1}{[2A_{0}]^{n-1}} \times \frac{1}{[A_{0}]^{n-1}}\)
\(2= \frac {[2A_{0}]^{n-1}} {[A_{0}]^{n-1}}\)
\(2= \frac {1} {2}^{n-1}\)
2 = (2^-1)^n-1
2¹ = (2^-n+1)
n = 0

37.

t_75% = 2t_50%
t_50% = (t_75%/2) = (60/2) = 30 minutes

38.

\({ t }_{ 1/2 }=\frac { 0.6932 }{ k } \)
For a second order reaction
\(\mathrm{t}_{1 / 2}=\frac{2^{\mathrm{n}-1}-1}{(\mathrm{n}-1) \mathrm{k} \cdot\left[\mathrm{A}_{0}\right]^{\mathrm{n}-1}}\)
n = 2
\(\mathrm{t}_{1 / 2}=\frac{2^{\mathrm{2}-1}-1}{(\mathrm{n}-1) \mathrm{k} \cdot\left[\mathrm{A}_{0}\right]^{\mathrm{2}-1}}\)
\(\mathrm{t}_{1 / 2} =\frac{1}{ \mathrm{k}\left[\mathrm{A}_{0}\right]}\)

39.

\(k=\frac { 2.303 }{ t } log\frac { \left[ { A }_{ 0 } \right] }{ \left[ A \right] } \)
2.303 x 10^-2 hour^-1 = \(\frac { 2.303 }{ 1806 min } log\frac { \left[ { 0.25 }_{ } \right] }{ \left[ A \right] } \)
\(=\left(\frac{2.303 \times 10^{-2} hour^{-1 }\times 1806 min}{2.303}\right) = \log \left(\frac{0.25}{A}\right) \)
\(=\left(\frac{ 1806 \times 10 ^{-2}}{60}\right) = \log \left(\frac{0.25}{A}\right) \)
\(= 0.301 = \log \left(\frac{0.25}{A}\right) \)
\(=\log2 = \log \left(\frac{0.25}{A}\right) \)
\(2 = \log \left(\frac{0.25}{A}\right) \)
\([A] = \log \left(\frac{0.25}{2}\right) = 0.125 M\)