Clinic Class Test 13 C E

Please read the instructions carefully. You are allotted 5 minutes specifically for this purpose.

Date : 14-03-2013

Duration : 1 Hour

Max. Marks : 80

CHEMISTRY (THERMO CHEMISTRY)

TEST - 13

INSTRUCTIONS

A. General :

1. This Question Paper contains 22 questions.

2. No additional sheets will be provided for rough work.

3. Blank paper, clipboard, log tables, slide rules, calculators, cellular phones, pagers and electronic gadgets in any form are not allowed.

4. The answer sheet, a machine-gradable Objective Response Sheet (ORS), is provided separately. 5. Do not Tamper / mutilate the ORS or this booklet.

6. Do not break the seals of the question-paper booklet before instructed to do so by the invigilators. 7. Write your Name, Roll No. and Sign in the space provide on the back page of this booklet.

B. Filling the bottom-half of the ORS :

Use only Black ball point pen only for filling the ORS. Do not use Gel / Ink / Felt pen as it might smudge the ORS.

8. Write your Roll no. in the boxes given at the top left corner of your ORS with black ball point pen. Also, darken the corresponding bubbles with Black ball point pen only. Also fill your roll no on the back side of your ORS in the space provided (if the ORS is both side printed).

9. Fill your Paper Code as mentioned on the Test Paper and darken the corresponding bubble with Black ball point pen.

10. If student does not fill his/her roll no. and paper code correctly and properly, then his/her marks will not be displayed and 5 marks will be deducted (paper wise) from the total.

11. Since it is not possible to erase and correct pen filled bubble, you are advised to be extremely careful while darken the bubble corresponding to your answer.

12. Neither try to erase / rub / scratch the option nor make the Cross (X) mark on the option once filled. Do not scribble, smudge, cut, tear, or wrinkle the ORS. Do not put any stray marks or whitener anywhere on the ORS.

13. If there is any discrepancy between the written data and the bubbled data in your ORS, the bubbled data will be taken as final.

C. Question paper format and Marking scheme :

14. The question paper consists of 1 parts. The part consists of Two Sections.

15. For each question in Section–I, you will be awarded 3 marks if you darken the bubble(s) corresponding to the correct choice for the answer and zero mark if no bubbled is darkened. In case of bubbling of incorrect answer, minus one (–1) mark will be awarded.

16. For each question in Section–II, you will be awarded 5 marks if you darken the bubble corresponding to the correct answer and zero marks if no bubble is darkened. In case of bubbling of incorrect answer, minus

one (–1) mark will be awarded.

D O N O T B R E A K T H E S E A L S W IT H O U T B E IN G IN S T R U C T E D T O D O S O B Y T H E I N V IG IL A T O R

C O D E

0

COURSE NAME : VIKAAS (JA) & VIPUL (JB)

COURSE CODE : CLINIC CLASSES

RESONANCE

Atomic masses : [H = 1, D = 2, Li = 7, C = 12, N = 14, O = 16, F = 19, Na = 23, Mg = 24, Al = 27, Si = 28,

P = 31, S = 32, Cl = 35.5, K = 39, Ca = 40, Cr = 52, Mn = 55, Fe = 56, Cu = 63.5, Zn = 65, As = 75, Br = 80, Ag = 108, I = 127, Ba = 137, Hg = 200, Pb = 207]

SECTION - I

Straight Objective Type

This section contains 15 questions. Each question has 4 choices (A), (B), (C) and (D) for its answer, out of which ONLY ONE is correct.

1. The enthalpy of neutralisation of a weak monoacidic base(1M) with strong acid is –56.9 KJ/mol. If the

enthalpy of ionisation of weak monoacidic base is 1.8 KJ/mol the ionisation of weak base in its molar solution is [Given that Hneutralisation of strong acid and strong base = –57.3 KJ/mol]

(A) 100/3 (B) 200/3 (C) 25% (D) None of these

2. Under the same condition how many mL of 0.1 M NaOH and 0.05 M H₂A (strong diprotic acid) solution should be mixed for a total volume of 100 mL produce the highest rise in temperature :

(A) 25 : 75 (B) 50 : 50 (C) 75 : 25 (D) 66.66 : 33.33

3. Only N₂, CO and CO₂ gases remain after 0.72 gm of carbon is treated with one litre of air at 27ºC and 4.92

atm pressure. Assume air composition O₂ = 20%, N₂ = 79% and CO₂ = 1% (by volume). The heat evolved (in Kcal) under constant pressure is :

Given : C + O₂  CO

2, H = – 100 Kcal/mol

C + ₂1O₂  CO, _H = _{– 25 Kcal/mol}

(A) 1 kcal (B) 2 kcal (C) 3 kcal (D) 4 kcal

RESONANCE

Space for Rough Work

4. H_fº of HgO (s) is 20 kcal/mol. The mass (in gm) of mercury, which can be liberated if 800 cal of heat is given

to excess of HgO (s) is :

(A) 8 g (B) 12 g (C) 16 g (D) 20 g

5. The standard heat of combustion of ethene gas is 330 Kcal mol–1 _{calculate bond energy( in kcal/}

mol) assuming that bond energy of C–H bond is 93.6 KCal mol–1

Given : Hºf for CO2(g) and H2O () are –94.2 and –61 Kcal mol–1 respectively. Heat of atomisation of carbon

and hydrogen are 150 and 51.5 Kcal mol–1 _{respectively.}

(A) 82 Kcal/mol (B) 92 Kcal/mol (C) 102 Kcal/mol (D) 112 Kcal/mol

6. A substance XY₃ decomposes as :

XY₃

The ratio of partial pressure of XY and XY₂ in the mixture of gases obtained by decomposition of XY₃ g) is 2 : 1. Find the total enthalpy change for the decomposition of 1 mole of XY₃.

(A) 53.33 kJ/mol (B) 160 kJ/mol (C) 110 kJ/mol (D) 1110.33 kJ/mol

7. If bond energy of H₂, F₂ and HF are in the ratio 2 : 1 : 3 and H_a (H₂) = 400 kJ/mol. Then H_ƒ (HF) is :

RESONANCE

Space for Rough Work

8. 2Fe +

2 3

O₂  Fe₂O₃ x kJ / mole

2Fe + O₂  2FeO y kJ / mole

The H to form one mole of Fe3O4 from Fe and O2 is :

(A) 2 x + y (B) 2 y x 2  (C) 2 y x 2  (D) 2 x 2 y

9. One gram of an organic liquid X (molecular mass 78) liberates 160 J of heat on solidification. Hfusion (A) is :

(A) 19.2 kJ/mol (B) 12.48 kJ/mol (C) 124.8 kJ/mol (D) None of these

10. Bond energies are equal to dissociation energies in case of :

(A) monoatomic molecules (B) polyatomic molecules

RESONANCE

Space for Rough Work

11. S(rhombic) + O₂  SO₂, H = – 297.5 kJ

S(monoclinic) + O₂  SO₂, H = – 300 kJ

This data indicates :

(A) Rhombic sulphure is yellow in colour (B) monoclinic sulphur is more stable (C) monoclinic sulphur has metallic lustre

(D) The process S(rhombic)  S(monoclinic) is endothermic

12. The difference between H and E (on a molar basis) for the combustion of n-octane () at 25°C would be :

(A) – 13.6 kJ (B) – 1.14 kJ (C) – 11.15 kJ (D) + 11.15 kJ 13. Statement-1 : The enthalpy of formation of H₂O() is greater than of H2O (g) in magnitude.

Statement-2: Enthalpy change is negative for the condensation reaction

H₂O (g)  H₂O()

(A) Statement-1 is True, Statement-2 is True; Statement-2 is a correct explanation for Statement-1. (B) Statement-1 is True, Statement-2 is True; Statement-2 is NOT a correct explanation for Statement-1 (C) Statement-1 is True, Statement-2 is False

RESONANCE

Space for Rough Work

14. In Haber's process of manufacturing of ammonia :

N₂(g) + 3H₂(g)  2NH₃(g) ; H0_25C = –92.2 kJ

Molecule N₂(g) H₂(g) NH₃(g)

C_P JK-1 _mol–1 _{29.1 28.8 35.1}

If C_P is independent of temperature, then reaction at 100°C as compared to that of 25°C will be :

(A) More endothermic (B) Less endothermic (C) More exothermic (D) Less exothermic

15. STATEMENT-1 : Heat of neutralization of HCl and NaOH is same as that of H₂SO₄ with NaOH.

STATEMENT-2 : HCl, H₂SO₄ and NaOH are all strong electrolyte.

(A) Statement-1 is True, Statement-2 is True; Statement-2 is a correct explanation for Statement-1. (B) Statement-1 is True, Statement-2 is True; Statement-2 is NOT a correct explanation for Statement-1 (C) Statement-1 is True, Statement-2 is False

(D) Statement-1 is False, Statement-2 is True

SECTION - II

Multiple Correct Answer Type

This section contains 7 questions. Each question has 4 choices (A), (B), (C) and (D) for its answer, out of which ONE OR MORE is/are correct.

16. In which of the following changes, Hº is always negative :

(A) enthalpy of solution (B) enthalpy of hydrogenation

RESONANCE

Space for Rough Work

17. The standard heat of combustion of solid boron is not equal to :

(A) H°_f (B₂O₃) (B) 1/2 H°_f (B₂O₃) (C) 2H°_f (B₂O₃) (D) 1/2 H°_f (B₂O₃) 18. The following is (are) endothermic reaction(s) :

(A) Combustion of methane. (B) Decomposition of water

(C) Dehydrogenation of ethane to ethylene. (D) Conversion of graphite to diamond.

19. Enthalpy of polymerisation of ethylene, as represented by the reaction, nCH₂=CH₂CH₂CH₂)_n is 100 kJ per mole of ethylene. Given bond enthalpy of C=C bond is 600 kJ mol1, enthalpy of CC bond (in kJ

mol) will be :

(A) 2940 kcal mol–1 _{(B) 350 kJ mol}–1 _{(C) 700 kJ mol}–1 _{(D) 1470 kcal mol}–1

20. Heat of hydrogenation of ethene is x₁ and that of benzene is x₂. Therefore Resonance energy value cannot be :

(A) x₁– x₂ (B) x₁ + x₂ (C) 3x₁– x₂ (D) x₁– 3x₂

21. C(s, graphite)  C(g) , following process is :

(A) Hºcombustion (B) Hºformation (C) Hºatomization (D) Hºsublimation

22. C (s, graphite) + O₂(g)  CO₂(g) , following process is :