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#### Sample 1 Mark Book Back Questions (New Syllabus) 2020

12th Standard EM

Reg.No. :
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Chemistry

Time : 00:20:00 Hrs
Total Marks : 28

Part A

28 x 1 = 28
1. Which of the metal is extracted by Hall-Heroult process?

(a)

Al

(b)

Ni

(c)

Cu

(d)

Zn

2. Oxidation state of carbon in its hydrides

(a)

+4

(b)

-4

(c)

+3

(d)

+2

3. On hydrolysis, PCl3 gives

(a)

H3PO3

(b)

PH3

(c)

H3PO4

(d)

POCl3

4. 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

5. Which of the following compounds is colourless?

(a)

Fe3+

(b)

Ti4+

(c)

Co2+

(d)

Ni2+

6. Which of the following lanthanoid ions is diamagnetic?

(a)

Eu2+

(b)

Yb2+

(c)

Ce2+

(d)

Sm2+

7. 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

8. 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+

9. Solid CO2 is an example of

(a)

Covalent solid

(b)

metallic solid

(c)

molecular solid

(d)

ionic solid

10. The vacant space in bcc lattice unit cell is

(a)

48%

(b)

23%

(c)

32%

(d)

26%

11. Among the following graphs showing variation of rate constant with temperature (T) for a reaction, the one that exhibits Arrhenius behavior over the entire temperature range is

(a)

(b)

(c)

(d)

both (b) and (c)

12. The addition of a catalyst during a chemical reaction alters which of the following quantities? (NEET)

(a)

Enthalpy

(b)

Activation energy

(c)

Entropy

(d)

Internal energy

13. 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)

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

14. pH of a saturated solution of Ca(OH)2 is 9. The Solubility product ( Ksp) of Ca(OH)2

(a)

0.5 ×10-15

(b)

0.25 ×10-10

(c)

0.125 ×10-15

(d)

0.5 ×10-10

15. Using Gibb’s free energy change, ∆Go=57.34 kJ mol-1, for the reaction, X2Y(s)⇌2X++Y2- (aq), calculate the solubility product of X2Y in water at 300 K (R = 8.3 J K-1Mol-1)

(a)

10-10

(b)

10-12

(c)

10-14

(d)

can not be calculated from the given dat

16. Which of the following can act as lowery – Bronsted acid well as base?

(a)

HCl

(b)

SO42−

(c)

HPO42−

(d)

Br-

17. The molar conductivity of a 0.5 mol dm-3 solution of AgNO3 with electrolytic conductivity of 5.76 ×10−3 S cm−1at 298 K is

(a)

2.88 S cm2mol-1

(b)

11.52 S cm2mol-1

(c)

0.086 S cm2mol-1

(d)

28.8 S cm2 mol -1

18. Zinc can be coated on iron to produce galvanized iron but the reverse is not possible. It is because

(a)

Zinc is lighter than iron

(b)

Zinc has lower melting point than iron

(c)

Zinc has lower negative electrode potential than iron

(d)

Zinc has higher negative electrode potential than iron

19. A certain current liberated 0.504gm of hydrogen in 2 hours. How many grams of copper can be liberated by the same current flowing for the same time in a copper sulphate solution

(a)

31.75

(b)

15.8

(c)

7.5

(d)

36.5

20. Statement :
To stop bleeding from an injury, ferric chloride can be applied. Which comment about the statement is justified?

(a)

It is not true, ferric chloride is a poison.

(b)

It is true, Fe3+ ions coagulate blood which is a negatively charged sol

(c)

It is not true; ferric chloride is ionic and gets into the blood stream.

(d)

It is true, coagulation takes place because of formation of negatively charged sol with Cl-.

21. 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

22. on treatment with Con H2SO4, predominately gives

(a)

(b)

(c)

(d)

23. Among the following ethers which one will produce methyl alcohol on treatment with hot HI?

(a)

(H3C)-3C-|-O-CH3

(b)

(CH3-)2-CH-CH2-O-CH3

(c)

CH3-(CH2)3-O-CH3

(d)

CH3-CH2-$\underset { \overset { | }{ { CH }_{ 3 } } }{ CH }$-O-CH3

24. 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

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

(a)

CH3CONHCH3

(b)

CH3 CH2CONH2

(c)

CH3CONH2

(d)

C6H5CONH2

26. The central dogma of molecular genetics states that the genetic information flows from

(a)

Amino acids Protein DNA

(b)

DNA Carbohydrates Proteins

(c)

DNA RNA Proteins

(d)

DNA RNA Carbohydrates

27. 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)

28. Saccharin, an artificial sweetener is manufactured from

(a)

cellulose

(b)

toluene

(c)

cyclohexene

(d)

starch