Question Set A

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

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Questions:

Multiple Choice Question

50 x 1 = 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

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

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

Secondary nitro alkanes react with nitrous acid to form _______.

(a)

red solution

(b)

blue solution

(c)

green solution

(d)

yellow solution

When aniline reacts with acetic anhydride the product formed is_______.

(a)

o – aminoacetophenone

(b)

m-aminoacetophenone

(c)

p – aminoacetophenone

(d)

acetanilide

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

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

(a)

carboxylic acid

(b)

aromatic acid

(c)

schiff ’s base

(d)

ketone

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

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

10.

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

(a)

CH₃CONHCH₃

(b)

CH₃CH₂CONH₂

(c)

CH₃CONH₂

(d)

C₆H₅CONH₂

11.

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

12.

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

13.

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.

14.

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

15.

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

16.

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

17.

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)

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

18.

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

19.

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)

20.

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

21.

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

22.

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

23.

The crystal with a metal deficiency defect is ________.

(a)

NaCl

(b)

FeO

(c)

ZnO

(d)

KCl

24.

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

25.

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)

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

26.

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)

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

27.

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

28.

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)

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

29.

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

30.

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

31.

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)

32.

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

33.

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

34.

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)

35.

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

36.

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

37.

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

38.

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

39.

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

40.

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

41.

The most common oxidation state of actinoids is _______.

(a)

(b)

(c)

(d)

42.

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

(a)

(b)

(c)

(d)

43.

Which of the following lanthanoid ions is diamagnetic?

(a)

Eu²⁺

(b)

Yb²⁺

(c)

Ce²⁺

(d)

Sm²⁺

44.

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.

45.

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

(a)

(b)

(c)

0.6

(d)

1.5

46.

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

(a)

(b)

(c)

(d)

47.

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

48.

The magnetic moment of Mn²⁺ ion is _______.

(a)

5.92BM

(b)

2.80BM

(c)

8.95BM

(d)

3.90BM

49.

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⁺

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)

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Answers Key:

Multiple Choice Question

50 x 1 = 50

(b)
Benzyl alcohol

(d)
N,N – dimethyl – 3- methyl - pentan - 3 amine

(b)
2,4 – dimethyl aniline

(b)
blue solution

(d)
acetanilide

10.

(a)
CH₃CONHCH₃

11.

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

12.

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

13.

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

14.

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

15.

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

16.

(a)
First order

17.

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

18.

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

19.

(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.

20.

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

21.

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.

22.

(a)
XY₈

23.

(b)
FeO

24.

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

25.

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

26.

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

27.

(a)
excitation of electrons in F centers

28.

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

29.

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

30.

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

31.

\(k=A{ e }^{ -\left( \frac { { E }_{ a } }{ RT } \right) }\)
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.

32.

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

33.

\(k=\frac { 2.303 }{ t } log\frac { \left[ { A }_{ 0 } \right] }{ \left[ A \right] } \)
\(k=\frac { 1 }{ t } ln \frac { \left[ { A }_{ 0 } \right] }{ \left[ A \right] } \)
\(e^{kt}=\frac { \left[ { A }_{ 0 } \right] }{ \left[ A \right] }\)
[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

34.

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

35.

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

36.

37.

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

38.

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

39.

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

40.

(a)
Np, Pu, Am

41.

(b)
+3

42.

(d)
+3

43.

Yb²⁺ - 4f¹⁴ - no unpaired electrons - diamagnetic

44.

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

45.

+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