12th Standard Chemistry English Medium Free Online Test One Mark Questions with Answer Key 2020 - Part Three

12th Standard

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Chemistry

Time : 00:25:00 Hrs
Total Marks : 25
25 x 1 = 25
1. Considering Ellingham diagram, which of the following metals can be used to reduce alumina? (NEET-2018)

(a)

Fe

(b)

Cu

(c)

Mg

(d)

Zn

2. Identify the metal that occurs in free state

(a)

Al

(b)

Au

(c)

Mg

(d)

Ca

3. Which of the following is not sp2 hybridised?

(a)

Graphite

(b)

graphene

(c)

Fullerene

(d)

dry ice

4. The catalytic behaviour of transition metals and their compounds is ascribed mainly due to

(a)

their magnetic behaviour

(b)

their unfilled d orbitals

(c)

their ability to adopt variable oxidation states

(d)

their chemical reactivity

5. In which of the following coordination entities the magnitude of Δ0 will be maximum?

(a)

[Co(CN)6]3-

(b)

[Co(C2O4)]3-

(c)

[Co(H2O)6]3+

(d)

[Co(NH3)6]3+

6. Co-ordination isomerism is exhibited by

(a)

[Cr(en)2Cl2]NO2

(b)

[Pt(NH3)4] [CuCl4]

(c)

[Cr(en)2Cl2]NO

(d)

[Co(NH3)5Cl]Cl2

7. Werner's theory was not able to explain______________ of coordination compounds

(a)

colour

(b)

magnetic properties

(c)

both (a) and (b)

(d)

neither (a) nor (b)

8. The number of unit cells in 8 gm of an element X ( atomic mass 40) which crystallizes in bcc pattern is (NA is the Avogadro number)

(a)

6.023 x 1023

(b)

6.023 x 1022

(c)

60.23 x 1023

(d)

$\left( \cfrac { 6.023\times { 10 }^{ 23 } }{ 8\times 40 } \right)$

9. The crystal with a metal deficiency defect is

(a)

NaCl

(b)

FeO

(c)

ZnO

(d)

KCl

10. A binary solid A+B- has a structure with B- ions constituting the lattice and A+ ions occupying 25% tetrahedral holes. Formula of the solid is

(a)

A2B

(b)

AB2

(c)

AB

(d)

AB4

11. The addition of a catalyst during a chemical reaction alters which of the following quantities? (NEET)

(a)

Enthalpy

(b)

Activation energy

(c)

Entropy

(d)

Internal energy

12. During decomposition of an activated complex

(a)

energy is always released

(b)

energy is always absorbed

(c)

energy does not change

(d)

products may be formed.

13. A solution which is resistant to changes of pH on addition of small amounts of an acid or a base is known as

(a)

buffer solution

(b)

true solution

(c)

isohydric solutionideal solution

(d)

ideal solution

14. The metal to be protected from corrosion is treated with cone HNO3 The process is called ________

(a)

galvanzin

(b)

passivation

(c)

cathodicprotection

(d)

formation of alloys

15. Which one of the is not a surfactant?

(a)

CH3 -(CH2)15 -N -(CH3)2 CH2Br

(b)

CH3 -(CH2)15 -NH2

(c)

CH3 -(- CH2- )-16CH2 OSO2- Na+

(d)

OHC-(CH2)14 -CH2 -COO- Na+

16. Assertion : Phenol is more acidic than ethanol
Reason: Phenoxide ion is resonance stabilized
Codes:
(a) if both assertion and reason are true and reason is the correct explanation of assertion.
(b) if both assertion and reason are true but reason is not the correct explanation of assertion.
(c) assertion is true but reason is false
(d) both assertion and reason are false.

(a)

if both assertion and reason are true and reason is the correct explanation of assertion.

(b)

if both assertion and reason are true but reason is not the correct explanation of assertion.

(c)

assertion is true but reason is false

(d)

both assertion and reason are false.

17.  is __________

(a)

Mesitylene

(b)

Pyrogallol

(c)

Hydroxy quinol

(d)

Phluroglucinol

18. Which one of the following reduces tollens reagent

(a)

formic acid

(b)

acetic acid

(c)

benzophenone

(d)

none of these

19. Identify 'X'.

(a)

(b)

(c)

(d)

20. $Phenol\overset { Zn }{ \underset { dust }{ \longrightarrow } } 'X'\overset { { CH }_{ 3 }Cl }{ \underset { anhy\ AlC{ I }_{ 3 } }{ \longrightarrow } } Y\overset { alk }{ \underset { { KMnO }_{ 4 } }{ \longrightarrow Z } }$ the product Z is __________.

(a)

benzaldehyde

(b)

benzoic acid

(c)

benzone

(d)

toluene

21. Identify X in the sequence give below

(a)

(b)

(c)

(d)

22. Nitrobenzene on electrolytic reduction in con. sulphuric acid, the intermediate formed is

(a)

C6H5NH - NHC6H5

(b)

C6H5 - NHOH

(c)

C6H5 - N = N - C6H5

(d)

C6H5HSO4

23. Sucrose contains glucose and fructose linked by

(a)

C1 - C1

(b)

C1-C2

(c)

C1 - C4

(d)

C1 - C6

24. Amino acids are linked covalently by ________bonds.

(a)

hydrogen

(b)

Co-ordinate

(c)

both (a) and (b)

(d)

peptide

25. Cholesterol is an example of_________

(a)

protein

(b)

vitamin

(c)

carbohydrat

(d)

lipid