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

12th Standard

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Chemistry

Time : 00:25:00 Hrs
Total Marks : 25
Answer all the questions
25 x 1 = 25
1. 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

2. In Hall-Herold process___________act as an, anode.

(a)

Carbon blocks

(b)

hydrogen

(c)

copper rods

(d)

Zinc rods

3. Silicones are ______

(a)

ortho silicates

(b)

water repellent thermal insulators

(c)

both (a) and (b)

(d)

None of these

4. An element belongs to group 15 and 3 rd 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

5. Which one of the following is not correct?

(a)

La(OH)2 is less basic than Lu(OH)3

(b)

In lanthanoid series ionic radius of Ln3+ ions decreases

(c)

La is actually an element of transition metal series rather than lanthanide series

(d)

Atomic radii of Zr and Hf are same because of lanthanide contract

6. _________ is known as Bayer's reagent.

(a)

Hot dilute alkaline KMnO4

(b)

Cold dilute alkaline KMnO4

(c)

Hot Conc. acidic KMnO4

(d)

Cold Conc. acidic KMnO4

7. Choose the correct statement

(a)

Square planar complexes are more stable than octahedral complexes

(b)

The spin only magnetic moment of [Cu(Cl)4]2- is BM and it has square planar structure.

(c)

Crystal field splitting energy $\left( { \Delta }_{ 0 } \right)$ [FeF6]4- is higher than the $(\Delta _{ 0 })$ $[Fe(CN)6]{ { 4 }^{ - } }$

(d)

crystal field stabilization energy of [V(H2O)6]2+ is higher than the crystal field stabilization of [Ti(H2O)6]2+

8. The oxidation state of the central metal ion in the complex [Co(H2O)(CN)(en)2]2+ is____________

(a)

0

(b)

+1

(c)

+2

(d)

+3

9. A two dimensional solid pattern formed by two different atoms X and Y is shown below. The black and white squares represent atoms X and Y respectively. the simplest formula for the compound based on the unit cell from the pattern is

(a)

XY8

(b)

X4Y9

(c)

XY2

(d)

XY4

10. Graphite is a good conductor of electricity due to the presence of____________

(a)

Lone pair of electrons

(b)

Free valence electrons

(c)

Cations

(d)

Anions

11. The correct difference between first and second order reactions is that (NEET)

(a)

A first order reaction can be catalysed; a second order reaction cannot be catalysed.

(b)

The half life of a first order reaction does not depend on [A0]; the half life of a second order reaction does depend on [A0].

(c)

The rate of a first order reaction does not depend on reactant concentrations; the rate of a second order reaction does depend on reactant concentrations.

(d)

The rate of a first order reaction does depend on reactant concentrations; the rate of a second order reaction does not depend on reactant concentrations.

12. 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.

13. MY and NY3, are insoluble salts and have the same Ksp values of 6.2 ×10-13 at room temperature. Which statement would be true with regard to MY and NY3?

(a)

The salts MY and NY3 are more soluble in 0.5M KY than in pure water

(b)

The addition of the salt of KY to the suspension of MY and NY3 will have no effect on their solubility’s

(c)

The molar solubilities of MY and NY3 in water are identical

(d)

The molar solubility of MY in water is less than that of NY3

14. For two acids A and B, Ka values at 25°C are 2 x 106 and 1.8 x 10-4 respectively. which among the following is true with respect to the above data.

(a)

A and B are equally acidic

(b)

A is stronger than B

(c)

B is stronger than A

(d)

Ka value is not a measure of acid strength

15. Which of the following electrolytic solution has the least specific conductance

(a)

2N

(b)

0.002N

(c)

0.02N

(d)

0.2N

16. An example for 1 : 1 electrolyte is

(a)

H2SO4

(b)

Na2SO4

(c)

NaCI

(d)

Al2(SO4)3

17. The coagulation values in millimoles per litre of the electrolytes used for the coagulation of AS2S3 are given below
(I) (NaCl)=52 (II) ((BaCl2)=0.69 (III) (MgSO4)=0.22
The correct order of their coagulating power is

(a)

III > II > I

(b)

I > II > III

(c)

I > III > II

(d)

II > III>I

18. Which of the following interface cannot be obtained?

(a)

solid - solid

(b)

solid - liquid

(c)

gas - gas

(d)

liquid -Iiquid

19. The process of removing ions from a sol by diffusion through a permeable membrane is called

(a)

Ultra filtration

(b)

Dialysis

(c)

Eletrophoresis

(d)

Cataphoresis

20. An example of lyophilic colloid is__________

(a)

sulphur in water

(b)

phosphorus in water

(c)

starch

(d)

all of these

21. It has no α- hydrogen

(a)

CH3CH2OH

(b)

CH3- CH2- CH2- OH

(c)

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

(d)

22. Complete the reaction

(a)

(b)

(c)

(d)

none

23. Of the following, which is the product formed when cyclohexanone undergoes aldol condensation followed by heating?

(a)

(b)

(c)

(d)

24. The major product of the following reaction

(a)

(b)

(c)

(d)

25. Which of the following are epimers

(a)

D(+)-Glucose and D(+)-Galactose

(b)

D(+)-Glucose and D(+)-Mannose

(c)

Neither (a) nor (b)

(d)

Both (a) and (b)