4. Which one of the following has the minimum boiling point? a) n-butane b) Isobutane c) 1-Butene d) 1- Butyne Ans: b

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1 1. Arrange the following according to bond strength: (a) (b) (c) (d) 2. Alcoholic solution of KOH is a specific reagent for (A) Dehydration (B) Dehydrogenation (C) Dehydro halogenation (D) Dehalogenation 3. During the preparation of ethane by Kolbe s electrolytic method using inert electrodes the ph of the electrolyte (A) Increases progressively as the reaction proceeds (B) Decreases progressively as the reaction proceeds (C) Remains constant throughout the reaction (D) May decrease of the the concentration of the electrolyte is not very high Solution: During the preparation of ethane by Kolbe s electrolytic method using inert electrodes the ph of the electrolyte 2CH3COONa + 2H2O CH3 CH3 + 2CO2 + H2 + 2NaOH Since NaOH is formed, the ph increases as the proceeds 4. Which one of the following has the minimum boiling point? a) n-butane b) Isobutane c) 1-Butene d) 1- Butyne Ans: b Boiling points follow the order Boiling points follow the order alkyne > alkene > n-alkane > branched alkane branched alkane. 5. Pure methane can be produced by a) Wurtz reaction b) Kolbe s electrolytic method c) Soda-lime decarboxylation d) reduction with H2 ANSWER: c 6. Anti Markownikoff s addition of HBr is not observed in (A) Propene (B) But 2 ene (C) Butene (D) Pent 2 ene 7.

2 A and B are geometrical isomers (R CH=CH R) (A) A is trans, B is cis (B) A and B both are cis (C) A and B both are trans (D) A is cis, B is trans 8. A compound (C 5 H 8 ) reacts with ammonical AgNO 3 to give a white precipitate and reacts with excess of KMnO 4 solution to give (CH 3 ) 2 CH COOH. The compound is (A) CH 2 =CH CH=CH CH 3 (B) (CH 3 ) 2 CH CºCH (C) CH 3 (CH 2 ) 2 CºCH (D) (CH 3 ) 2 C=C=CH Product X is: (A) (B) (C) (D) Depends on Temperature

3 11. R 1 and R 2 are (A) Cold alkaline KMnO 4, OsO 4 /H 2 O 2 (C) Cold alkaline KMnO 4, CH 3 O O CH 3 (B) Cold alkaline KMnO 4, HCO 3 H (D) C 6 H 5 CO 3 H, HCO 3 H Which reagent is the most useful for distinguishing compound I from the rest of the compounds CH 3 CH 2 CºCH CH 3 CºCCH 3 CH 3 CH 2 CH 2 CH 3 CH 3 CH=CH 2 I II III IV (A) alk. KMnO 4 (B) Br 2 /CCl 4 (C) Br 2 /CH 3 COOH (D)Ammonical AgNO 3 Ans: (D) 14. Which will have the highest heat of hydrogenation: (A) 1-butene (b) cis-2-butene (c) trans-2-butene (d) butane 15. A and B are (A) alcoholic KOH and NaNH 2 (B) NaNH 2 and alcoholic KOH (C) NaNH 2 and Lindlar (D) Lindlar and NaNH 2

4 For questions 16-18, use the data given below: 1 mole of ideal monoatomic gas at 27 C expands adiabatically against a constant external pressure of 1.5 atm from a volume of 4dm 3 to 16 dm q for the above change is: (a) 20 J (b) 10 J (c) -10 J (d) zero Ans: (d) 17. W for the above change is: (a) zero (b) 18 atm dm 3 (c) + 18 atm dm 3 (d) 100 atm dm for the above change is: (a) zero (b) 18 atm dm 3 (c) + 18 atm dm 3 (d) 100 atm dm Which of the following statement(s) is/are true? (i) A closed system shows exchange of mass and not energy with surroundings. (ii) Entropy change for fusion reaction is positive. (iii) Heat is a measure of quantity of energy whereas temperature is a measure of intensity of energy. (A) (i),(ii) (B) (ii), (iii) (C) (iii), (i) (D)all three 20. The heat of transition for carbon from diamond to graphite from the following data is Solution: CDiamond + O2(g) CO2(g) H = 94.3 kcal CAmorphous + O2(g) CO2(g) H = 97.6 kcal (A) 3.3 kj / mol (B) 3.3 kcal / mol (C) 3.3 kj / mol (D) 3.3 kcal / mol Given CD + O2(g) CO2(g) H = 94.3 kcal/mole (1) CA + O2(g) CO2(g) H = 97.6 kcal/mole (2) Subtracting equation (2) from equation (1): CD CA 0; H = +3.3 kcal/mole H = +3.3 kcal/mole CD CA

5 (B) 21. For a system C(s) + O2(g) = CO2(g) which of the following is correct: (a) H = E (b) H E (c) H E (d) H = An athelete is given 100 gm glucose of energy equivalent to 1760 kj. He utilizes 50% of this gained energy in an event. In order to avoid storage of energy in his body, he has to perspire. Calculate the wt of water he would need to perspire given enthalpy of HOfor evaporation is 44 kj / mole. 2 (a) 100 gm (b) 180 gm (c) 360 gm (d) 720 gm Sol. Energy gained by athelete = 1760 kj Energy utilized in event = 50% of 1760 kj Energy left = = 880 kj Since 44 kj energy used to evaporate = 18 gm HO kj energy used to evaporate = 360 gm of H2O For Questions 23 & 24, use data from the passage given below: The specific heat at constant volume for a gas cal / g and at constant pressure is cal / gm. 23. The molecular weight of the gas is: (a) 20 (b) 30 (c) 40 (d) Atomicity of the gas is: (a) 1 (b) 2 (c) 3 (d) A system is taken from state A to state B along two different paths 1 and 2. The heat absorbed and work done by the system along these paths are Q1 and Q2 and W1 and W2 respectively. Then Sol. (A) Q1 = Q2 (C) W1 = W2 (D) (B) W1 + Q1 = Q2 + W2 (D) Q1 W1 = Q2 W2 26. Bomb calorimeter is used for determining change in internal energy at constant (A) Pressure (B) Temperature

6 (C) Volume (D) Humidity 27. Evaporation of water is a spontaneous process although it (A) Is an exothermic reaction (B) is an endothermic reaction (C) Is a photo chemical reaction (D) proceeds without heat loss or heat gain 28. The heats of neutralization of four acids a, b c and d when neutralized against a common base are 13.7, 9.4, 11.2 and 12.4 Kcal respectively. The weakest among these acids is (A) c (C) a Ans: (D) (B) d (D) b For questions 29 & 30: The questions given below consist of statements Assertion (A) and Reason (R). (a) If both A and R are correct and R is correct reason for A. (b) If both A and R are correct but R is not the correct explanation for A. (c) If A is true but R is false. (d) If both A and R are false. 29. (A) When a gas at high pressure expands against vacuum the work done is maximum. (R) Work done in expansion depends upon the pressure inside the gas & increase in volume. Ans: (D) 30. (A) A reaction which is spontaneous & accompanied by decrease of randomness must be exothermic. (R) All exothermic reaction are accompanied by decrease of randomness.

I. Multiple Choice Questions (Type-I)

Unit 13 HYDROCARBONS I. Multiple Choice Questions (Type-I) 1. Arrange the following in decreasing order of their boiling points. (A) n butane (B) 2 methylbutane (C) n-pentane (D) 2,2 dimethylpropane A