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

12th Standard

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Chemistry

Time : 00:25:00 Hrs
Total Marks : 25
25 x 1 = 25
1. Wolframite ore is separated from tinstone by the process of ________

(a)

Smelting

(b)

Calcination

(c)

Roasting

(d)

Electromagnetic separation

2. The incorrect statement among the following is

(a)

Nickel is refined by Mond’s process

(b)

Titanium is refined by Van Arkel’s process

(c)

Zinc blende is concentrated by froth floatation

(d)

In the metallurgy of gold, the metal is leached with dilute sodium chloride solution

3. 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 : ${ Fe }_{ 2 }{ O }_{ 3 }3C\rightarrow 3CO+2Fe$

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

(a)

Aluminium

(b)

calcium

(c)

Magnesium

(d)

sodium

5. The geometry at which carbon atom in diamond are bonded to each other is __________

(a)

Tetrahedral

(b)

graphene

(c)

Fullerene

(d)

dry ice

6. An element belongs to group 15 and 3rd period of the periodic table, its electronic configuration would be _____________

(a)

1s2 2s2 2p4

(b)

1s2 2s2 2p3

(c)

1s2 2s2 2p6 3s2 3p2

(d)

1s2 2s2 2p6 3s2 3p3

7. The basicity of pyrophosphorous acid ( H4P2O5) is __________

(a)

4

(b)

2

(c)

3

(d)

5

8. The magnetic moment of Mn2+ ion is ___________

(a)

5.92BM

(b)

2.80BM

(c)

8.95BM

(d)

3.90BM

9. Coinage metals are _________

(a)

normal metals

(b)

transition metals

(c)

active metals

(d)

alkali metals

10. An excess of silver nitrate is added to 100ml of a 0.01M solution of pentaaquachloridochromium(III)chloride. The number of moles of AgCl precipitated would be ___________

(a)

0.02

(b)

0.002

(c)

0.01

(d)

0.2

11. Which one of the following pairs represents linkage isomers?

(a)

[Cu(NH3)4][ptCl4] and [pt(NH3)4][CuCl4]

(b)

[Co(NH3)5(NO3)]SO4 and [Co(NH3)5(ONO)]

(c)

[Co(NH3)4(NCS)2]ct and [Co(NH3)4(SCN)2]Cl

(d)

both (b) and (c)

12. The geometry of [Ni(CN)4]2- is

(a)

Tetrahedral

(b)

Square planar

(c)

Triangular

(d)

Octahedral

13. Phthalo blue - a bright blue figment is a complex of ________________

(a)

Copper (I) ion

(b)

Copper (II) ion

(c)

Nickel (II) ion

(d)

Nickel (IV) ion

14. 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

15.  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)

$\left( \cfrac { 1 }{ 2 } a;\cfrac { \sqrt { 3 } }{ 2 } a;\cfrac { \sqrt { 2 } }{ 2 } a \right)$

(b)

$\left( \sqrt { 1a } :\sqrt { 3a } :\sqrt { 2a } \right)$

(c)

$\left( \cfrac { 1 }{ 2 } a:\cfrac { \sqrt { 3 } }{ 4 } a:\cfrac { 1 }{ 2\sqrt { 2 } } a \right)$

(d)

$\cfrac { 1 }{ 2 } a:\sqrt { 3 } a:\cfrac { 1 }{ \sqrt { 2 } } a$

16. The crystal with a metal deficiency defect is __________

(a)

NaCl

(b)

FeO

(c)

ZnO

(d)

KCl

17. 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

18. In a reversible reaction, the enthalpy change and the activation energy in the forward direction are respectively −x kJ mol-4 and kJ mol-1 Therefore, the energy of activation in the backward direction is ________

(a)

(y-x)kJ mol-1

(b)

(x+y)J mol-1

(c)

(x-y)KJ mol-1

(d)

(x+y) x 103Jmol-1

19. In a homogeneous reaction $A\longrightarrow B+C+D$ the initial pressure was P0 and after time t it was P. expression for rate constant in terms of P0, P and t will be _________

(a)

$k=\left( \cfrac { 2.303 }{ t } \right) log\left( \cfrac { 2{ P }_{ 0 } }{ { 3P }_{ 0 }-P } \right)$

(b)

$k=\left( \cfrac { 2.303 }{ t } \right) log\left( \cfrac { { 2P }_{ 0 } }{ { P }_{ 0 }-P } \right)$

(c)

$k=\left( \cfrac { 2.303 }{ t } \right) log\left( \cfrac { 3{ P }_{ 0 }-P }{ 2P_{ 0 } } \right)$

(d)

$k=\left( \cfrac { 2.303 }{ t } \right) log\left( \cfrac { 2{ P }_{ 0 } }{ { 3P }_{ 0 }-2P } \right)$

20. Which will make basic buffer?

(a)

50 mL of 0.1M NaOH+25mL of 0.1M CH3 COOH

(b)

100 mL of 0.1M CH3COOH+100 mL of 0.1M NH4OH

(c)

100 mL of 0.1M HCl+200 mL of 0.1M NH4OH

(d)

100 mL of 0.1M HCl+100 mL of 0.1M NaOH

21. Which of the following relation is correct for degree of hydrolysis of ammonium acetate?

(a)

$h=\sqrt { \frac { { K }_{ h } }{ C } }$

(b)

$h=\sqrt { \frac { { K }_{ h } }{ K_b } }$

(c)

$h=\sqrt { \frac { { K }_{ h } }{ { K }_{ a }.{ K }_{ b } } } \\$

(d)

$h=\sqrt { \frac { { { K }_{ a }.{ K }_{ b } } }{ { K }_{ h } } } \\$

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. Carbolic acid is __________

(a)

Phenol

(b)

Picri cacid

(c)

benzoic acid

(d)

phenylacetic acid

24. (a)

(b)

(c)

(d)

25. Which of the following amino acids are achiral?

(a)

Alanine

(b)

Leucine

(c)

Proline

(d)

Glycine