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

12th Standard EM

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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. Na[Ag(CN)2] is _________.

(a)

Sodium aurocyanide

(b)

Sodium meta aluminate

(c)

Aluminosilicate

(d)

Sodium dicyano argentate

3. Which of the following is not sp2 hybridised?

(a)

Graphite

(b)

graphene

(c)

Fullerene

(d)

dry ice

4. All elements except carbon have the tendency to show maximum covalency of six ______

(a)

due to presence of vacant d-orbitals

(b)

due to absence of vacant d-orbitals

(c)

due to presence of partially filled d-orbitals

(d)

due to presence of completely filled d-orbitals

5. In acid medium, potassium permanganate oxidizes oxalic acid to

(a)

oxalate

(b)

Carbon dioxi

(c)

acetate

(d)

acetic acid

6. The correct statement is,

(a)

Cu2Cl2 and Ag2S are coloured

(b)

Upon strong heating paramagnetic gases are evolved by NaNO3 and AgNO3

(c)

Green vitriol and blue vitriol are isomorphus

(d)

KMnO4 and K2Cr2O7 are coloured due to

7. Which of the following is paramagnetic in nature?

(a)

[Zn(NH3)4]2+

(b)

[Co(NH3)6]3+

(c)

[Ni(H2O)6]2+

(d)

[Ni(CN)4]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. For the reaction, 2NH3 ⟶ N2 + 3H2, if $\frac { -d[NH_{ 3 }] }{ dt }$=k1[NH3], $\frac { d[N_{ 2 }] }{ dt } =k_{ 2 }[NH_{ 3 }],\frac { d[{ H }_{ 2 }] }{ dt }$=k3[NH3] then the relation between k1, k2 and k3 is

(a)

k1=k2=k3

(b)

k1=3k2=2k3

(c)

1.5k1=3k2=k3

(d)

2k1=k2=3k3

10. For an exothermic chemical process occurring in 2 steps as
(i) A +B ⟶ X (slow) ;
(ii) X ⟶  AB (fast)
The progress of the reaction can be best described by (x- intermediate).

(a)

(b)

(c)

(d)

None of these

11. Equal volumes of three acid solutions of pH 1,2 and 3 are mixed in a vessel. What will be the H+ ion concentration in the mixture?

(a)

3.7 ×10-2

(b)

10-6

(c)

0.111

(d)

none of these

12. Which one of the following formula represents Ostwald's dilution law for a binary whose degree of dissociation is a and concentration C.

(a)

$K=\frac{(1-α)C}{α}$

(b)

$K=\frac{α^2C}{1-a}$

(c)

K = $\frac{(1-a)C}{a^2}$

(d)

K = $\frac{α^2C}{(1-α)c}$

13. SHE is ___________

(a)

Standard Helium Electorde

(b)

Standard Hydrogen Electrode

(c)

Standard Mercury Electrode

(d)

none of these

14. The oxidation of sodium sulphite by air is retarded by

(a)

MnO2

(b)

H2S

(c)

Alcohol

(d)

AS2O3

15. In the reaction sequence, Ethane $\overset { HOCl }{ \longrightarrow } A\overset { x }{ \longrightarrow }$ ethan -1, 2 - diol . A and X respectively are

(a)

Chloroethane and NaOH

(b)

ethanol and H2SO4

(c)

2 – chloroethan -1-ol and NaHCO3

(d)

ethanol and H2O

16. The number of secondary alcoholic group in glycerol is ________

(a)

1

(b)

2

(c)

3

(d)

0

17. Which of the following represents the correct order of acidity in the given compounds

(a)

FCH2COOH > CH3COOH > BrCH2COOH > ClCH2COOH

(b)

FCH2COOH > ClCH2COOH > BrCH2COOH > CH2COOH

(c)

CH3COOH > ClCH2COOH > FCH2COOH > Br-CH2COOH

(d)

Cl CH2COOH > CH3COOH > BrCH2COOH > ICH2COOH

18. Pick out the compound that reduces Tollen's reagent and Fehling's solution.

(a)

CH3CHO

(b)

CH3COCH3

(c)

CH3COOH

(d)

both (a) and (b)

19. The reduction of CH3 - CH2 - C ☰ N with sodium and alcohol results in the formation of

(a)

${ CH }_{ 3 }-\underset { \overset { | }{ { NH }_{ 2 } } }{ CH } -{ CH }_{ 3 }$

(b)

CH3- CH2- CH2- OH + N2

(c)

CH3 - CH2 - CH2 - NH2

(d)

CH3 - CH2 - NH2

20. Vitamin B2 is also known as

(a)

Riboflavin

(b)

Thiamine

(c)

Nicotinamide

(d)

Pyridoxine

21. An example for reducing disaccharide is

(a)

glucose

(b)

fructose

(c)

sucrose

(d)

lactose

22. The properties of protein are determined by___________

(a)

nature of the amino acids

(b)

the position of NH2 group

(c)

the position of COOH group

(d)

all

23. 2-acetoxy benzoic acid is used as an _________

(a)

anti malarial

(b)

antihistamine

(c)

antipyretic

(d)

antidepressant

24. Proteins which act as biological catalysts are called ________

(a)

enzymes

(b)

hormones

(c)

vitamins

(d)

polymers

25. Cellulose is an example of _____ polymer.

(a)

synthetic

(b)

Natural

(c)

semisynthetic

(d)

none of the above