eamcet 2011 engg

CHEMISTRY CREST EAMCET – 2011(ENGINEERING)

http://www.chemistrycrest.com/

Maximum Marks: 40 Question paper format and Marking scheme: 1. This question paper has 40 questions of equal weight age. Each question is allotted 1 mark for each correct response. 2. No deduction from the total score will be made if no response is indicated for an item in the answer sheet. 3. There is only one correct response for each question. Filling up more than one response in each question will be treated as wrong response



121. The number of radial nodes present in the radial probability distribution curves for the orbital wave function with quantum numbers n = 4, l = 0 and m = o is:

(1) 4 (2) 3 (3) 2 (4) 1 Sol. (2) Number of radial nodes in Radial probability distribution curves ( )1 4 0 1 3n l= − − = − − =

122. If the uncertainty in velocities of two particles A and B with mass 271.0 10−× kg ad 311.0 10−× kg

respectively is the same, the ratio of uncertainty in the positions of A and B is: (1) 1000 : 1 (2) 10,000 : 1 (3) 1 : 1000 (4) 1 : 10,000 Sol. (4)

( ) ( ). .4

hx m v

π∆ ∆ =

( )v∆ same for both A and B

h, 4 and π are constants x m∴∆ ∝

( )( )

311 10271 10

mx A Bx mB A

−∆ ×∴ = = −∆ ×

410 1

1 10,000

−= =

123.

With reference to the diagram given the van dar Waals radius is equal to

(1) 'A A− (2) B-A (3) B-D (4) A-C Sol. (4) Half the distance between centres of two atoms of different molecules which are closest to each other ( held together by vanderwaal’s forces )is called vanderwaal’s radius Vander Waals radius = A - C



124. In which one of the following, the bond angle is the lowest?

(1) H O3

⊕ (2) N H

4

⊕ (3) F O

2 (4) BCl

3

Sol. (3)

Bond angles : ( ) ( )3+ 01 H O 1073

sp−

( ) ( )3 0 '2 109 284

N H sp+

−

( ) ( )3 03 1032

F O sp−

( ) ( )2 04 1203

BCl sp−

125. In the Born-Haber cycle of the given reaction

( ) ( ) ( )s g s

1Na + Cl NaCl

22→

The number of endothermic and exothermic stages respectively are: (1) 2, 3 (2) 3, 1 (3) 3, 2 (4) 2, 2 Sol. (3) Steps invoved in Born haber cycle of the reaction

( ) ( ) ( )s g s

1Na + Cl NaCl

22→

1) Sublimation of solid Na ( ) ( ) ; 108.7 /s gNa Na H KJ mole→ ∆ = +

2)Dissociation of Cl2 molecules

2( ) ( )

1; 119.55 /

2 g gCl Cl H KJ mole→ ∆ = +

3)Formation of Na+ ions

( ) ( ) ; 492.82 /g gNa Na e H KJ mole+ −→ + ∆ = +

4)Formation of Cl- ions

( ) ( ) ; 361.60 /g gCl e Cl H KJ mole− −+ → ∆ = −

5)Formation of NaCl

( ) ( ) ( ); /g g sNa Cl NaCl H UKJ mole+ −+ → ∆ = −

Number of endothermic stages( ∆H = + ve) = 3 ( 1, 2 and 3) Number of exothermic stages( ∆H = - ve) = 2 ( 4 and 5)



126. A metal nitride contains 28% nitrogen by weight. The molecular formula of metal nitride is M N

3 2. What is the atomic weight of metal?

(1) 72 (2) 64 (3) 100 (4) 24 Sol. (4) % of nitrogen = 28; % of metal = 72 As per formula M3N2, 2× At. wt. of nitrogen = 2×14 = 28 ∴3×At. wt. of metal = 72 Therefore, atomic weight of metal = 24 127. Which one of the following statements is not correct?

(1) The fraction of total number of molecules of a gas having most probable velocity increases with an increase in temperature of the gas. (2) The concentration of an ideal gas at 100 K ad 0.0821 atm. of pressure is -2 11.0 10 mol.lit−× (R = 0.0821 lit. atm 1 1mol .K− −

(3) If the rms velocity of an ideal gas at T(K) is ‘C’ cm.s-1, its rms velocity at 4T(K) is ‘2C’ cm.s-1 (4) The average kinetic energy of gas molecules is proportional to their absolute temperature. Sol. (1) Acc to Maxwell – Boltzmann distribution curves of molecular velocities, most probable velocity increases but total no of molecules having most probable velocity decreases 128. In acidic medium, 100 ml of 0.01 M KMnO4 solution oxidizes 100 ml of H2O2 solution. The volume

of 0.01 M KMnO4 required to oxidizes the same volume of H2O2 in alkaline medium in ml. is

(1) 300

2 (2)

300

5 (3)

500

3 (4)

500

2

Sol. (3)

Acid medium : 28 5 44 2

MnO H e Mn H O− + − ++ + → +

Alkaline medium : 4 3 44 2 2

MnO H O e MnO OH− − −+ + → +

Volume of 0.01 KMnO4 required in acid medium = 100 ml.

∴Volume of 0.01M KMnO4 required in alkaline medium = 100 5 500

3 3ml

× =

129. A solution of 10 g of a non-volatile binary electrolyte (mol. Wt = 100) in 500 g of water freezes at

00.74 C− . What is the degree of ionization? ( fK of water = 1.85 K Molality-1)

(1) 50% (2) 75% (3) 100% (4) 0% Sol. (3)



. .

10 10000 (0.74) 1.85

100 500

fT i k mf

i

∆ =

×− = × ××

2i =

1 2 1

11 2 1

i

nα − −= = =

− −

∴degree of ionization = 100%

130. For the electrochemical cell ( )0 +M M X X,E M | M+ − = 0.44 V and ( )0E X | X 0.33V− = . Which one

of the following is true for this data?

(1) +M + X M + X −→ is a spontaneous reaction

(2) +M +X M + X− → is a spontaneous reaction

(3) E 0.77 Vcell

=

(4) E 0.77Vcell

=−

Sol. (2) Cell : M M X X+ −

When SRP values are given, 0 00E E E

cell right left= −

0E 0.33 0.44 0.11Vcell

= − = −

Therefore , the given cell reaction is non spontaneous Reverse reaction, i.e.,

+M +X M + X− →

is spontaneous

131. In electrochemical corrosion, the metal undergoing corrosion: (1) Acts as anode (2) Acts as cathode (3) Undergoes reduction (4) Liquefies Sol. (1) The metal undergoing corrosion acts as anode.

132. If the length of the unit cell is 0

5A between the two neighbouring metal atoms in a face centred cubic lattice is:

(1) 2.50 (2) 5.00 (3) 7.07 (4) 3.535 Sol. (4) Unit cell length, a = 5A0

In FCC lattice, nearest neighbouring distance =2

ad = = 05

3.5362

A=



133. Match the following:

List –I List –II

(A) Arrhenius equation (i) Free energy change

(B) Slowest step in a reaction mechanism (ii) Conc-1. time-1

(C) Rate constant of a II order reaction

(iii) 1 n 1conc .time− −

(D) The possibility of a reaction depends on (iv) Rate determining stop

(v) E /RTnk A,e

−=

A B C D (1) v I iii iv (2) v iv iii ii (3) v iv ii i (4) iii iv ii i Sol. (3)

(A) Arrhenius equation: /. Ea RTK A e−= (B) Slowest step in reaction mechanism is rate determining step (C)Units of rate constant of n th order reaction is

11 1. nnlit mole time−− −

Where n is order of the reaction

Rate constant of 2nd order reaction

1 1 1.lit mole time− −= 1 1.Conc time− −

(D) Possibility of a reaction depends on free energy If ∆G0 = -ve , the reaction is spontaneous If ∆G0 = +ve , the reaction is non spontaneous If ∆G0 = 0 , the reaction is at equilibrium 134. At T(K), the partial pressures of SO2, O2 and SO3 are 0.662, 0.100 and 0.331 atm. respectively for

the reaction ( ) ( ) ( )

2 2 3g g g

2SO O 2SO+ ��⇀�↽�� at equilibrium. What is the partial pressure in atm. of O2

when the equilibrium partial pressures of SO2 and SO3 are equal at the same temperature? (1) 0.4 (2) 08 (3) 0.25 (4) 2.5 Sol. (1)

( ) ( ) ( )

2 2 3g g g

2SO O 2SO+ ��⇀�↽��

2 2(0.331)32 2. (0.662) 1

2 2

PSO

Kp P P

So O

= =×

1

0.4=



21 3

20.4 .2 2

P SO

P PSO O

= ( )3 2

P PSO SO

=

0.4atm2

PO

∴ =

135. The order of pH of 0.200 M solutions of NH4NO3, NaNO3 and Na2CO3 is:

(1) 4 3 2 3 3NH NO <Na CO <NaNO (2) 24 3 3 3NH NO <NaNO <Na CO

(3) 42 3 3 3Na CO <NaNO <NH NO (4) 43 3 2 3NaNO < NH NO Na CO<

Sol. (2) NH4NO3 is a salt of weak base( NH4OH) and strong acid( HNO3). ∴Acidic, pH < 7 NaNO3 is a salt of strong base( NaOH) and strong acid ( HNO3).∴Neutral pH = 7 Na2CO3 is a salt of strong base( NaOH) and weak acid( H2CO3 ) ∴ Basic pH > 7 ∴ order of pH of the solutions : 24 3 3 3NH NO <NaNO <Na CO

136. Which one of the following pairs represents the intensive properties? (1) Specific heat and temperature (2) Entropy and density (3) Enthalpy and mole fraction (4) Heat and temperature Sol (1) Specific heat and temperature are intensive properties, independent of the system size or the amount of material in the system . 137. According to Langmiur adsorption isotherm, the amount of gas adsorbed by unit surface area is: (a, b, k and n are constants; P = pressure of gas)

(1) nk,P (2) 1+bP

aP (3) 1/nk.P (4)

aP

1+bP

Sol. (4)

Langmuir adsorption isotherm, 1

x ap

m bp=

+

138. Calcium carbide is hydrolyzed using heavy water. What are the products formed? (1) ( )Ca OH ,C D2 2 2

(2) ( )Ca OD ,C D2 2 2

(3) ( )Ca OD ,CD2 4 (4) ( )Ca OH ,CD2 4

Sol. (2) Calcium carbide on deuterolysis gives Calcium deuteroxide and Deutero acetylene

( )2 2 22 2 2 2CaC D O Ca OD C D+ → +



139. The reactivity of Ca, Sr, Mg and Ba with water follow the order: (1) Sr > Ba > Mg > Ca (2) Ba > Sr > Ca > Mg (3) Ca > Mg > Ba > Sr (4) Sr > Ca > Mg > Ba Sol. (2) Reactivity with of given alkaline earth metals with water follows the order: Ba > Sr > Ca > Mg 140. Electro negativity of group 13 elements follow the order: (1) B > Ga > Al > Tl > In (2) B > Tl > Ga > Al > In (3) B > Tl > ln > Ga > Al (4) B > Al > Tl > ln > Ga Sol. (3) E.N order of group 13 elements B > Tl > ln > Ga > Al 141. What is the empirical formula of sheet silicates?

(1) ( )2Si2 5

nO

n

− (2) ( )2SiO

3

n

n

− (3) ( )SiO

3

n

n

− (4) ( )3Si O

2 7

n

n

−

Sol. (1)

Empirical formula of sheet silicates is ( )2Si2 5

nO

n

−

142. The gases evolved in the decomposition of lead nitrate are: (1) N O , NO

2 3 (2) NO ,O

2 2

(3) N O ,O2 3 2

(4) N O,O2 2

Sol. (2)

( )2 2 43 2 22

Pb NO PbO NO O∆→ + +

143. Which of the following statements are correct? (I) Monoclinic sulphur contains S8 molecules (II) Sulphur forms SF6, SF4 and S2F2 (III) Peroxo group is present in H S O

2 2 6

(1) II, III (2) I, II (3) I, III (4) I, II, II I Sol. (2) Monoclinic sulphur contains S8 molecules. Sulphur forms SF6, SF2 and S2F2



144. Bond energy of F2, Cl2 and Br2 follow the order: (1) F F Cl Cl Br Br− > − > − (2) Cl Cl Br Br F F− > − > − (3) Br Br Cl Cl F F− > − > − (4) Cl Cl F F Br Br− > − > − Sol. (2) Bond energy order Cl Cl Br Br F F− > − > − 145. A mixture of He, Ne, Kr and Xe is cooled. Which one of them condenses first? (1) Xe (2) Ne (3) Kr (4) He Sol. (1) Xenon condenses as a liquid first. 146. The solution of X having excess caustic potash is used to detect ammonia. Which of the following is X?

(1) K HgI2 4

(2) ( )Co NH Cl3 36

(3) ( )K Fe NCS63 (4) ( )Co NH SO Br

3 45

Sol. (1)

2 4

K HgI

(Nessler’s reagent) is used to detect ammonia.

147. Which of the following metallurgical processes does not involve heating? (1) Smelting (2) Calcination (3) Roasting (4) Leaching Sol. (4) Leaching does not involve heating of ore. 148. Which one of the following is not a green-house gas? (1) CO2 (2) N2O (3) O3 (4) N2 Sol. (4) N2 is not a green house gas. 149. The reagent used to detect phosphorous in an organic compound is:

(1) FeSO4

(2) AgNO3

(3) ( )NH MoO4 4

(4) BaCl2

Sol. (3)

Ammonium molybdate(( )4 42NH MoO ) is used to detect phosphorous an organic compound.



150. Which one of the following alkenes gives only ethanal on ozonolysis? (1) Propane (2) 2-Butene (3) 1-Butene (4) 2-Pentene Sol. (2)

151. Which one of the following does not give precipitate with ammonical cuprous chloride? (1) H C CH C CH

3 2− − = (2) H C C CH

3− =

(3) HC CH= (4) H C C C CH3 3

− = −

Sol. (4) CH C C CH

3 3− ≡ − has no acidic hydrogen.So, it does not give precipitate with Ammonical cuprous

chloride. 152. The number of stereoisomers possible for ( ) ( )H C CH OH CH OH CH

3 3− − − is:

(1) 1 (2) 2 (3) 3 (4) 4 Sol. (3) Number of stereo isomers possible are 3( 2 optically active and 1 optically inactive)

153. PCl AgNO

5 2C H OH A B2 5

− → → . Identify A and B.

(1) C H Cl, C H O C H2 5 2 5 2 5

− − − (2) C H , C H O C H2 6 2 5 2 5

− −

(3) C H Cl, C H ONO2 5 2 5

− − (4) C H , C H NO2 6 2 5 2

Sol. (3)

PCl AgNO

5 2C H OH C H Cl C H O N O2 5 2 5 2 5

A B

→ → − − =

154. Assertion (A) : Ethanol boils at lower temperature than ethane. Reason (R) : The molecular weight of ethanol is higher than that of ethane. The correct answer is:

(1) Both A and R are true and R is the correct explanation of A (2) Both A and R are true but R is the correct explanation of A (3) A is true but R is not true (4) A is not true but R is true



Sol. (4) Ethanol boils at a higher temperature than Ethane since it has inter molecular hydrogen bonds The molecular weight of ethanol is higher than that of ethane. Mol. Wt. of ethanol = 46; Mol. Wt. of ethane = 30 155. Which compound is formed when mixture of calcium acetate and calcium formate is heated?

(1)

O

H C C CH2 3

− −�

(2)

O O

H C C O C CH3 3

− − − −� �

(3) HCHO (4) H C CHO3

−

Sol. (4)

( ) ( ) 2 223 3 32CH COO Ca HCOO Ca CH CHO CaCO

∆+ → +

156. Identify X in the following:

( )( )i NH

3H CCO H X3 2 ii ∆

→

(1) H CCN3

(2) H CCO NH3 2 4

(3) ( )H CCO O3 2

(4) H CCONH3 2

Sol. (4)

Reaction : 3 3 3 4 3 2 2

CH COOH NH CH COONH CH CONH H O

A

∆+ → → +

157. Carbylamine test is used to detect which one of the following? (1) C H CHO

6 5 (2) C H CO H

6 5 2

(3) C H NH6 5 2

(4) C H OH6 5

Sol. (3) Carbylamine test is used to detect pri aliphatic and aromatic amines as well as chloroform

3 3 36 5 2 3 6 5 2

alcC H NH CHCl KOH C H NC KCl H O+ + → + +

158. Proteins are: (1) Polysaccharides (2) Polynucleotides (3) Polypeptides (4) Trigycerides Sol. (3) Proteins are polypeptides.



159. Scurvy is caused by the deficiency of which vitamin? (1) C (2) B1 (3) D (4) B2 Sol. (1) Scurvy is a disease caused by the deficiency of vitamin C. 160. Which one of the following is a good preservative?

(1)

CO Na2

(2)

OH

CO C H2 2 5

(3)

OCOCH3

CO H2

(4)

OH

NHCOCH3

Sol. (1) Sodium benzoate is a food preservative.

eamcet 2011 engg

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