" /> -->

#### Model 1 Mark Book Back Questions (New Syllabus) 2020

12th Standard EM

Reg.No. :
•
•
•
•
•
•

Chemistry

Time : 00:35:00 Hrs
Total Marks : 47

Part A

47 x 1 = 47
1. Which of the following is incorrect with respect to metallurgy of iron in the blast furnace?

(a)

Zone of combustion : $C+{ O }_{ 2 }\rightarrow { CO }_{ 2 }$

(b)

Zone of heat absorption : ${ CO }_{ 2 }\rightarrow C+{ O }_{ 2 }$

(c)

Zone of slag formation : $CaO+{ SiO }_{ 2 }\rightarrow CaSiO_{ 3 }$

(d)

Zone of reduction : ${ Fe }_{ 2 }{ O }_{ 3 }3C\rightarrow 3CO+2Fe$

2. Which one of the following element is present as a~ impurity in pig iron?

(a)

Phosphorus

(b)

Manganese

(c)

Carbon

(d)

Silicon

3. Chemical formula of phosgene is

(a)

COCl2

(b)

CaOCl2

(c)

CaCO3

(d)

COCI

4. Identify the electron - deficient species

(a)

(BH3)2

(b)

(SiH3)2

(c)

PH3

(d)

(CH3)2

5. Hybridisation of chromium ions and dichromate ions is

(a)

Sp2

(b)

Sp3d

(c)

both (a) and (b)

(d)

None of these

6. Which one of the following exhibits highest oxidation state?

(a)

Ni

(b)

Mn

(c)

V

(d)

Zr

7. An aqueous solution of (PdCI)2 4NH3, when treated with excess of AgNO3 precipitated 2 moles of AgCI. Predict the secondary valency of the compound.

(a)

2

(b)

3

(c)

4

(d)

6

8. Naming the ligand in [M(en)2]n+starts with

(a)

Di

(b)

Bi

(c)

Bis

(d)

any of these

9. In an octahedral complex, the (n-1) d orbital are involved in hybridization. The complex is called _______________ complex

(a)

inner orbital

(b)

low spin

(c)

spin paired

(d)

all the above

10. In which of the following arrangements, octahedral voids are formed?

(a)

fcc

(b)

bcc

(c)

simple cubic

(d)

hcp

11. Which of the following is incorrect statement about the Bragg's equation nλ = 2d sin θ?

(a)

n, represents order of reflection

(b)

λ, represents wave length of uv-rays used

(c)

θ, represents angle of incidence

(d)

d, represents distance between two parallel planes

12. Crystalline solids are also called as

(a)

supercooled liquids

(b)

true solids

(c)

pseudo solids

(d)

all the above

13. The number of octahedral void(s) per atom present in a cubic close-packed structure is_________.

(a)

1

(b)

2

(c)

3

(d)

4

14. The coordination number of ZnS is _________.

(a)

3

(b)

4

(c)

6

(d)

8

15. The depletion of ozone involves the following steps:
Step 1: O2 +O $\overset { { k }_{ 1 } }{ \underset { { k }_{ 2 } }{ \rightleftharpoons } }$ O3 (fast)
Step 2: O3 +O $\overset { k }{ \longrightarrow }$ 2O2 (slow)
The predicted order of the reaction will be

(a)

I

(b)

II

(c)

III

(d)

Zero

16. Which of the following statement is not correct?

(a)

Molecularity of a reaction cannot be fractional

(b)

Molecularity of a reaction cannot be more than three

(c)

Molecularity of a reaction can be zero

(d)

Molecularity is assigned for each elementary step of mechanism.

17. When the Ea of a reaction zero then the rate constant of the reaction is equal to __________

(a)

2.303 K

(b)

$\frac { K }{ 2.303 }$

(c)

$\left( { t }_{ \frac { 1 }{ 2 } } \right)$

(d)

A

18. Analyses the equilibrium
HClO4 +H2O ⇌ H3O+ ${ ClO }_{ 4 }^{ - }$
and choose the correct statement.

(a)

H3O+ is the conjugate base of H2O

(b)

CIO4 is the conjugate base of HCIO4

(c)

H2O is the conjugate acid of H3O+

(d)

HCIO4 is the conjugate acid of H3O+

19. Which one of the following is correct?

(a)

pH = H+

(b)

pH = -log10 H+

(c)

pH = log10H+

(d)

pH = 2log10H+

20. Kohlraush's law is applied to calculate

(a)

molar conductance at infinite dilution of a weak electrolyte

(b)

degree of dissociation of weak electrolyte

(c)

solubility of a sparingly soluble salt

(d)

all the above

21. The laws of electrolysis were enunciated first by

(a)

Dalton

(b)

(c)

Kekule

(d)

22. The metals near the bottom of the electro chemical series are

(a)

strong reducing agents

(b)

strong oxidising agents

(c)

weak reducing agents

(d)

weak oxidising agents

23. Low molar conductivity at high concentration is due to _____________

(a)

High attractive force between oppositively charged ions

(b)

Viscous drag due to greater solvation

(c)

Both High attractive force between oppositively charged ions and Viscous drag due to greater solvation

(d)

Neither High attractive force between oppositively charged ions and Viscous drag due to greater solvation

24. Which of the following is true regarding Freundlich adsorption isotherm equation?

(a)

Purely empirical

(b)

Valid only over a limited pressure range

(c)

The value of constants k and n varies with temperature

(d)

All the above

25. Which one is the correct factor that explains the increase of rate of reaction by a catalyst?

(a)

Shape selectivity

(b)

Particle size

(c)

Increase of free energy

(d)

Lowering of activation energy

26. For W/O emulsion, the principle emulsifying agent is

(a)

proteins

(b)

synthetic soaps

(c)

lampblack

(d)

gums

27. Which one of the alcohol cannot be prepared by grignard reagent?

(a)

Methanol

(b)

ethanol

(c)

iso propyl alcohol

(d)

phenyl methanol

28. The reaction of Lucas reagent is fast with

(a)

(CH3)3 COH

(b)

(CH3)2 CHOH

(c)

CH3(CH2)2OH

(d)

CH3CH2OH

29. Which among the following has both local anaesthetic and antiseptic properties?

(a)

benzyl benzoate

(b)

phenol

(c)

benzyl alcohol

(d)

n-propyl alcohol

30. Baeyer's reagent is _______

(a)

ZnlHg in Cone HCI

(b)

acidified K2Cr2O7

(c)

cold alkaline KMnO4

(d)

Sodium borohydride

31. The number of secondary alcoholic group in glycerol is ________

(a)

1

(b)

2

(c)

3

(d)

0

32. Isomerism exhibited by ethylene glycol is ________

(a)

position isomerism

(b)

chain isomerism

(c)

functional isomerism

(d)

both (a) and (c)

33. The test used to distinguish wish 10, 20 and 30 alcohol is ________

(a)

Lucas test

(b)

Victor Meyer's

(c)

dehydrogenation

(d)

all the above

34. Intermolecular hydrogen bonds are not _______ present in

(a)

CH3 COOH

(b)

C2H5OC2H5

(c)

CH3CH2OH

(d)

C2H5NH2

35. Which among the carbonyl compounds cannot be prepared by Rosenmund reduction?

(a)

Ketones

(b)

Formaldehyde

(c)

Acetaldehyde

(d)

Both (a) and (b)

36. Hydrogenation of benzoyl chloride in the presence of Pd on BaSO4 gives

(a)

phenol

(b)

benzoic acid

(c)

benzyl alcohol

(d)

benzaldehyde

37. 4 - methyl pent - 3 ene - 2 - one is the IUPAC name of

(a)

mesitylene

(b)

mesityl oxide

(c)

phorone

(d)

chloretone

38. An example of pinacol is _______.

(a)

CH3-CH2OH

(b)

$\underset { \overset { | }{ \underset { \overset { | }{ { CH }_{ 2 }-OH } }{ CH-OH } } }{ { CH }_{ 2 }-OH }$

(c)

${ CH }_{ 3 }-\overset { \underset { | }{ { CH }_{ 3 } } }{ \underset { \overset { | }{ OH } }{ C } } -\overset { \underset { | }{ { CH }_{ 3 } } }{ \underset { \overset { | }{ OH } }{ C } } -{ CH }_{ 3 }$

(d)

both (b) and (c)

39. The most acidic among the following is ________.

(a)

p- nitrophenol

(b)

p- hydroxybenzoicacid

(c)

o- hydroxy benzoic acid

(d)

p- toluic acid

40. Which among the following reactions will give a secondary amine?

(a)

${ CH }_{ 3 }CO{ NH }_{ 2 }\underrightarrow { { Br }_{ 2 }/KOH }$

(b)

${ CH }_{ 3 }{ CONH }_{ 3 }\underrightarrow { { LIAlH }_{ 4 } }$

(c)

${ CH }_{ 3 }CN\xrightarrow [ Na/{ C }_{ 2 }{ H }_{ 5 }OH ]{ }$

(d)

${ CH }_{ 3 }NC\underrightarrow { { LiAlH }_{ 4 } }$

41. Which among the following exists as zwitter ion?

(a)

sulphanilic acid

(b)

salicylic acid

(c)

acetanilide

(d)

all the above

42. The organic compound that undergoes carbylamine reaction is

(a)

(C2H5)2NH

(b)

C2H5NH2

(c)

(C2H5)3 N

(d)

(C2H5)4 N+L-

43. CH3NO2+6[H] $\underrightarrow { X? }$ CH3NH2+2H2O. 'X' is

(a)

Sn/HCI

(b)

Zn/NH4CI

(c)

Glucose + NaOH

(d)

Na3A5O3/NaOH

44. The isomerism exhibited by 1-nitro butane and 1-nitro - 2- methyl propane is ______

(a)

chain

(b)

tautomerism

(c)

position

(d)

functional

45. Glucose is not oxidised to gluconic acid by

(a)

Br2/H2O

(b)

Fehling's solution

(c)

Tollen's reagent

(d)

Conc. HNO3

46. The ultimate product of hydrolysis of starch in the presence of dilute acid is

(a)

dextrin

(b)

maltose

(c)

maltase

(d)

glucose

47. The formulation of dettol contains

(a)

chloroxylenol

(b)

terpineol

(c)

alcohol

(d)

all of these