" /> -->

#### 12th Standard Chemistry English Medium Free Online Test Volume 1 One Mark Questions with Answer Key 2020

12th Standard EM

Reg.No. :
•
•
•
•
•
•

Chemistry

Time : 00:25:00 Hrs
Total Marks : 25
25 x 1 = 25
1. Which one of the following is not feasible

(a)

$Zn(s)+C{ u }^{ 2+ }\left( aq \right) \rightarrow Cu\left( s \right) +{ Zn }^{ 2+ }(aq)$

(b)

$Cu(s)+Z{ n }^{ 2+ }(aq)\longrightarrow Zn(s)+{ Cu }^{ 2+ }(aq)$

(c)

$Cu(s)+2Ag^{ + }(aq)\longrightarrow Ag(s)+{ Cu }^{ 2+ }(aq)$

(d)

$Fe(s)+{ Cu }^{ 2+ }(aq)\longrightarrow Cu(s)+{ Fe }^{ 2+ }(aq)$

2. The percentage of carbon in high carbon steel is_________

(a)

0.5 - 1%

(b)

0.15 - 1.5%

(c)

0.15 - 1.5%

(d)

0.15 - 0.3%

3. Which of the following metals has the largest abundance in the earth’s crust?

(a)

Aluminium

(b)

calcium

(c)

Magnesium

(d)

sodium

4. On hydrolysis, PCl3 gives

(a)

H3PO3

(b)

PH3

(c)

H3PO4

(d)

POCl3

5. Assertion : bond dissociation energy of fluorine is greater than chlorine gas
Reason: chlorine has more electronic repulsion than fluorine.

(a)

Both assertion and reason are true and reason is the correct explanation of assertion.

(b)

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

6. Which one of the following orders is correct for the bond dissociation enthalpy of halogen molecules?

(a)

Br2 > I2 > F2 > Cl2

(b)

F2 > Cl2 > Br2 > l2

(c)

I2 > Br2 > Cl2 > F2

(d)

Cl2 > Br2 > F2 > I2

7. The incorrect statement regarding structure of ozone is______

(a)

Bond angle is less than 120°

(b)

It is linear

(c)

The two oxygen-oxygen bond length in ozone are identical

(d)

Both (b) and (c).

8. The alloy of copper that contain Zinc is

(a)

Monel metal

(b)

Bronze

(c)

bell metal

(d)

brass

9. 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.

10. Oxygen stabilises higher oxidation state because

(a)

it is electronegative

(b)

of its tendency to form multiple bond

(c)

of large size

(d)

of small size

11. Electrode potential of M2+/M for Ni is abnormal because of _________

(a)

high lE1 + E2

(b)

high hydration energy

(c)

ΔH atomisation

(d)

Electronic configuration of Ni2+

12. A complex has a molecular formula MSOCl. 6HO42.The aqueous solution of it gives white precipitate with Barium chloride solution and no precipitate is obtained when it is treated with silver nitrate solution. If the secondary valence of the metal is six, which one of the following correctly represents the complex?

(a)

[M(H2O)4Cl]SO42H2O

(b)

[M(H2O)6]SO4

(c)

[M(H2O)5Cl]SO4H2O

(d)

[M(H2O)3Cl]SO4.3H2O

13. A magnetic moment of 1.73BM will be shown by one among the following (NEET)

(a)

TiCl4

(b)

[CoCl6]4-

(c)

[Cu(NH3)4]2+

(d)

[Ni(CN)4]2-

14. How many geometrical isomers are possible for<<EVA035.eps>>?

(a)

3

(b)

4

(c)

0

(d)

15

15. Which of the following octahedral complexes do not show geometrical isomerism?

(a)

[Co(NH3)3Cl3]

(b)

[PtCl2(NH3)4]

(c)

[Pt(NH3)2Cl2]

(d)

[Co(en)3]3+

16. The geometry of complex ion [Fe(CN)6]4- is

(a)

tetrahedral

(b)

square planar

(c)

octahedral

(d)

triangular

17. 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)

18. Magnetic moment is given by the formula

(a)

$\sqrt { n(n+1) }$

(b)

$\sqrt { n(n+2) }$

(c)

$\sqrt { (n+2) }$

(d)

$\sqrt { { n }^{ 2 }+(n+2) }$

19. 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

20. In calcium fluoride, having the flurite structure the coordination number of Ca2+ ion and F- Ion are (NEET)

(a)

4 and 2

(b)

6 and 6

(c)

8 and 4

(d)

4 and 8

21. An example of metal deficiency defect

(a)

NaCl

(b)

AgCl

(c)

CsCl

(d)

FeS

22. Three atoms P, Q and R crystallize in a cubic solid lattice having P atom at corners) Q atom at body centre and R atom at the face centres. Identify formula of the compound.

(a)

PQR

(b)

PQR2

(c)

PQR3

(d)

P3QR

23. Which one of the following statements is not true?

(a)

The heat of vaporisation of ionic crystals are high

(b)

Ionic crystals are soluble in non-polar solvent

(c)

Ionic crystals are hard and brittle

(d)

Ionic crystals are conductors in solution state

24. Which one of the following is a network solid?

(a)

diamond

(b)

silicon carbide

(c)

naphthalene

(d)

both (a) and (b)

25. The type of crystal system shown is __________.

(a)

Cubic

(b)

Orthorhombic

(c)

Mono clinic

(d)

Tetragonal