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#### 12th Standard Chemistry English Medium Free Online Test 1 Mark Questions 2020 - Part Three

12th Standard EM

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Chemistry

Time : 00:25:00 Hrs
Total Marks : 25
25 x 1 = 25
1. Which of the following will give respective metal by self reduction?

(a)

Galena (Pbs)

(b)

HgS

(c)

ZnS

(d)

Both (a) & (b)

2. Magnetic separation it is based on the difference in the_________ of the ore and the impurities.

(a)

magnetic properties

(b)

chemical properties

(c)

physical properties

(d)

melting point

3. In diborane, the number of electrons that accounts for banana bonds is

(a)

six

(b)

two

(c)

four

(d)

three

4. SiO44- ion has ____ geometry.

(a)

Triangular

(b)

Tetrahedral

(c)

Linear

(d)

Pentagonal bipyramidal

5. Solid (A) reacts with strong aqueous NaOH liberating a foul smelling gas(B) which spontaneously burn in air giving smoky rings. A and B are respectively

(a)

P4(red) and PH3

(b)

P4(white) and PH3

(c)

S8 and H2S

(d)

P4(white) and H2S

6. Thr hybridisation and shape of SF6 is respectively?

(a)

sp3d2,square planar

(b)

sp3d2,octahedral

(c)

sp3d see-saw

(d)

sp3d,trigonal bipyramindal

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

(a)

Ti

(b)

Cu

(c)

Mn

(d)

Zn

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

(a)

Ni

(b)

Mn

(c)

V

(d)

Zr

9. If the standard electrode potential (Eo) of a inetal is ____________ and ______________ the metal is a powerful reducing agent.

(a)

large, negative

(b)

large, positive

(c)

small, negative

(d)

small, positive

10. Oxidation state of Iron and the charge on the ligand NO in [Fe(H2O)5NO]SO4 are

(a)

+2 and 0 respectively

(b)

+3 and 0 respectively

(c)

+3 and -1 respectively

(d)

+1 and +1 respectively

11. Among the following complexes the one which shows zero crystal field stabilisation energy is

(a)

[Mn(H2O)6]3+

(b)

[Fe(H2O)6]3+

(c)

[CO(H2O)6]2+

(d)

[CO(H2O)6]3+

12. Consider the following statements and identify the incorrect statement(s).
(i) CN- is a powerful ligand.
(ii) Haemoglobin is a monomer and myoglobin is a tetramer.
(iii) Cis - Pt (NH3)2Cl2 is an anti-tumor drug.

(a)

only (i)

(b)

only (ii)

(c)

only (iii)

(d)

both (i) and (iii)

13. 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)

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

14. What is the relation between diamond and .graphite?

(a)

Polymorphous

(b)

Isomer

(c)

Isotope

(d)

Isomorphous

15. An element with atomic mass 60 having fee structure has a density of 6.23g/cm3. what is the edge length of unit cell?

(a)

200 Pm

(b)

300 Pm

(c)

400 Pm

(d)

500 Pm

16. If electrical conductivity is found to be I same in all directions through a solid the substance is __________ solid and the property is called _________

(a)

crystalline, isotropy

(b)

amorphous, isotropy

(c)

crystalline, anisotropy

(d)

amorphous, isotropy

17. 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 Ea = 0
(iii) rate constant k is equal to collision frequency A if Ea =0
(iv) a plot of ln (k) vs T is a straight line.
(v) a plot of ln (k) vs $\left( \cfrac { 1 }{ T } \right)$ 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)

18. Which of these is not likely to act as lewis base?

(a)

BF3

(b)

PF3

(c)

CO

(d)

F

19. HClis a strong acid since

(a)

It can be easily oxidised

(b)

It canbe easilyionised

(c)

It dissociates completely to give H+ ions in solution

(d)

It can be easily oxidised and It can be easilyionised

20. The cell constant of a conductivity cell is ____________

(a)

l x a

(b)

$\frac{a}{l}$

(c)

$\frac{l}{a}$

(d)

$\frac{l^2}{a}$

21. Oxidation takes place at _____________ and reduction takes place at __________

(a)

anode, cathode

(b)

cathode, anode

(c)

anode

(d)

cathode

22. Which one of the following is an example for homogeneous catalysis?

(a)

manufacture of ammonia by Haber’s process

(b)

manufacture of sulphuric acid by contact process

(c)

hydrogenation of oil

(d)

Hydrolysis of sucrose in presence of all HCl

23. In the reaction Ethanol $\overset { { PCl }_{ 5 } }{ \longrightarrow } X\overset { alc.KOH }{ \longrightarrow } Y\overset { { H }_{ 2 }{ SO }_{ 4 }/{ H }_{ 2 }O }{ \underset { 298k }{ \longrightarrow } } Z.$ The ‘Z’ is

(a)

ethane

(b)

ethoxyethane

(c)

ethylbisulphite

(d)

ethanol

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

(a)

CH3CONHCH3

(b)

CH3 CH2CONH2

(c)

CH3CONH2

(d)

C6H5CONH2

25. Which of the following vitamins is water soluble?

(a)

Vitamin E

(b)

Vitamin K

(c)

Vitamin A

(d)

Vitamin B