# Multiple choice question for engineering

## Set 1

1. Enthalpy of a stream is which function of temperature and pressure?

a) Explicit

b) Implicit

c) Cannot say

d) None of the mentioned

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2. In a reaction the feed is 10 moles of 0.1 glucose and 0.9 water, and another feed of 5 moles of 0.2 glucose and 0.8 water, what is the total moles of product?

a) 5

b) 10

c) 15

d) 20

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3. In a reaction the feed is 10 moles of 0.1 glucose and 0.9 water, and another feed of 5 moles of 0.4 glucose and 0.6 water, what is the fraction of glucose in the products?

a) 0.2

b) 0.4

c) 0.6

d) 0.8

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4. In a reaction the feed is 10 moles of 0.1 glucose and 0.9 water, and another feed of 5 moles of 0.4 glucose and 0.6 water, what is the fraction of water in the products?

a) 0.2

b) 0.4

c) 0.6

d) 0.8

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5. In a reaction the feed is 5 moles of 0.5 glucose and 0.5 sucrose, and another feed of 15 moles of 0.3 glucose and 0.7 sucrose, what is the fraction of glucose in the products?

a) 0.35

b) 0.45

c) 0.75

d) 0.95

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6. Two feeds, F_{1} with H = 10 J/mole and F_{2} with H = 20 J/mole, and product 10 moles with H = 15 J/mole, what is the F_{1}?

a) 5 mole

b) 10 mole

c) 15 mole

d) 20 mole

### View Answer

_{1}+ 20*F

_{2}= 10*15, => F

_{1}+ F

_{2}= 10, => F

_{1}= 5 mole.

7. Two feeds, F_{1} with H = 10 J/mole and F_{2} with H = 25 J/mole, and product 15 moles with H = 15 J/mole, what is the F_{2}?

a) 5 mole

b) 10 mole

c) 15 mole

d) 20 mole

### View Answer

_{1}+ 25*F

_{2}= 15*15, => F

_{1}+ F

_{2}= 15, => F

_{2}= 5 mole.

8. Two feeds, 10 moles with H = 10 J/mole and 5 with H = 25 J/mole, what is the enthalpy of products?

a) 5 J/mole

b) 10 J/mole

c) 15 J/mole

d) 20 J/mole

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9. Two feeds, 15 moles with H = 10 J/mole and 10 with H = 20 J/mole, what is the enthalpy of products?

a) 8 J/mole

b) 12 J/mole

c) 18 J/mole

d) 25 J/mole

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10. Two feeds, F_{1} with H = 10 J/mole and 5 moles with H = 20 J/mole, if the mole of products is 10 what is the enthalpy of products?

a) 10 J/mole

b) 15 J/mole

c) 20 J/mole

d) 25 J/mole

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11. Three feeds, 10 mole with H = 5 J/mole, 10 mole with H = 15 J/mole and 5 mole with 20 J/mole, what is the enthalpy of the products?

a) 10 J/mole

b) 12 J/mole

c) 15 J/mole

d) 24 J/mole

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12. Three feeds, 10 mole with H = 25 J/mole, 5 mole with H = 10 J/mole and 15 mole with 20 J/mole, what is the enthalpy of the products?

a) 10 J/mole

b) 12 J/mole

c) 20 J/mole

d) 28 J/mole

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13. Three feeds, 10 mole with H = 15 J/mole, 20 mole with H = 5 J/mole and F_{1} with 20 J/mole, if enthalpy of the products is H = 15 J/mole, what is the value of F_{1}?

a) 10 mole

b) 20 mole

c) 30 mole

d) 40 mole

### View Answer

_{1}*20 = (30 + F

_{1})*15, => F

_{1}= 40 mole.

14. Two feeds, 10 mole with 5 J/mole and 20 mole with 15 J/mole, product contains two streams, 5 mole with 10 J/mole and P with 25 J/mole, what is the value of P?

a) 10 mole

b) 12 mole

c) 15 mole

d) 18 mole

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15. Two feeds, 5 mole with 25 J/mole and F with 5 J/mole, product contains two streams, 5 mole with 10 J/mole and 10 mole with 15 J/mole, what is the value of F?

a) 10 mole

b) 15 mole

c) 20 mole

d) 25 mole

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## Set 2

1. A reactor is supplied with 6 moles of CO and 3 moles of O_{2} and produced 4 moles of CO_{2}, what is the extent of reaction?

a) 1

b) 2

c) 3

d) 4

### View Answer

_{2}-> 2CO

_{2}, => Extent of reaction = (4 – 0)/2 = 2.

2. A reactor is supplied with 6 moles of N_{2} and 9 moles of H_{2}, if 3 moles of NH_{3} is produced, how many moles of H_{2} are left at the end?

a) 1.5

b) 3

c) 4.5

d) 6

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_{2}+ 3H

_{2}-> 2NH

_{3}, => extent of reaction = (3 – 0)/2 = 1.5, => moles of H

_{2}left = 9 – 1.5*3 = 4.5.

3. A reactor is supplied with 10 moles of CH_{4} and 10 moles of O_{2}, if the extent of reaction is 3, what are the moles of CO_{2} produced?

a) 3

b) 6

c) 8

d) 12

### View Answer

_{4}+ 2O

_{2}-> CO

_{2}+ 2H

_{2}O, => moles of CO

_{2}produced = 3*1 = 3.

4. A reactor is supplied with 10 moles of O_{2} and 10 moles of H_{2}, if the extent of reaction is 5, how many moles of water is produced?

a) 5

b) 10

c) 15

d) 20

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_{2}+ O

_{2}-> 2H

_{2}O, => moles of H

_{2}O produced = 5*2 = 10.

5. A reactor is supplied with 5 moles of KNO_{3} and some H_{2}SO_{4}, if the extent of reaction is 2, how many moles of H_{2}SO_{4} were supplied?

a) 1

b) 2

c) 5

d) Cannot be determined

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_{2}SO

_{4}are not given, initial moles cannot be determined.

6. A reactor is supplied with a 100 mole feed of composition 46% C_{3}H_{7}O_{4}, 44% O_{2} and 10% N_{2}, if 50% of the limiting reagent is converted into product, what is the extent of reaction?

a) 1

b) 2

c) 3

d) 4

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_{3}H

_{7}O

_{4}+ 11O

_{2}-> 12CO

_{2}+ 14H

_{2}O, => limiting reagent is O

_{2}, => Extent of reaction = (44*0.5 – 44)/(-11) = 2.

7. A reactor is supplied with a feed of composition 46% C_{3}H_{7}O_{4}, 44% O_{2} and 10% N_{2}, if 50% of the limiting reagent is converted into product, what is the percentage of O_{2} in the product?

a) 10

b) 18

c) 38

d) 54

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_{3}H

_{7}O

_{4}+ 11O

_{2}-> 12CO

_{2}+ 14H

_{2}O, => Limiting reagent is O

_{2}. Let 100 moles of feed was supplied, => after the reaction, moles of CO

_{2}= 24, moles of H

_{2}O = 28, moles of O

_{2}= 22, moles of C

_{3}H

_{7}O

_{4}= 38, moles of N

_{2}= 10, => percentage of O

_{2}= 18%.

8. A reactor is supplied with a feed of composition 46% C_{3}H_{7}O_{4}, 44% O_{2} and 10% N_{2}, if 50% of the limiting reagent is converted into product, what is the percentage of N_{2} in the product?

a) 8

b) 18

c) 34

d) 46

### View Answer

_{3}H

_{7}O

_{4}+ 11O

_{2}-> 12CO

_{2}+ 14H

_{2}O, => Limiting reagent is O

_{2}. Let 100 moles of feed was supplied, => after the reaction, moles of CO

_{2}= 24, moles of H

_{2}O = 28, moles of O

_{2}= 22, moles of C

_{3}H

_{7}O

_{4}= 38, moles of N

_{2}= 10, => percentage of N

_{2}= 8%.

9. A reactor is supplied with a feed of composition 46% C_{3}H_{7}O_{4}, 44% O_{2} and 10% N_{2}, if 50% of the limiting reagent is converted into product, what is the percentage of C_{3}H_{7}O_{4} in the product?

a) 10

b) 16

c) 31

d) 43

### View Answer

_{3}H

_{7}O

_{4}+ 11O

_{2}-> 12CO

_{2}+ 14H

_{2}O, => Limiting reagent is O

_{2}. Let 100 moles of feed was supplied, => after the reaction, moles of CO

_{2}= 24, moles of H

_{2}O = 28, moles of O

_{2}= 22, moles of C

_{3}H

_{7}O

_{4}= 38, moles of N

_{2}= 10, => percentage of C

_{3}H

_{7}O

_{4}= 31%.

10. A reactor is supplied with a feed of composition 46% C_{3}H_{7}O_{4}, 44% O_{2} and 10% N_{2}, if 50% of the limiting reagent is converted into product, what is the percentage of H_{2}O in the product?

a) 15

b) 23

c) 39

d) 51

### View Answer

_{3}H

_{7}O

_{4}+ 11O

_{2}-> 12CO

_{2}+ 14H

_{2}O, => Limiting reagent is O

_{2}. Let 100 moles of feed was supplied, => after the reaction, moles of CO

_{2}= 24, moles of H

_{2}O = 28, moles of O

_{2}= 22, moles of C

_{3}H

_{7}O

_{4}= 38, moles of N

_{2}= 10, => percentage of H

_{2}O = 23%.

11. A reactor is supplied with two steams with equal flow rates, stream-1 containing 75% SO_{2}, 25% N_{2} and stream-2 containing pure H_{2}S, if the product has 1200 grams of S, and the ratio of H_{2}S to H_{2}O is 5 and the ratio of SO_{2} to H_{2}S is 2, what is the rate of streams?

a) 10 mole

b) 20 moles

c) 30 moles

d) 40 moles

### View Answer

_{2}S + SO

_{2}-> 3S + H

_{2}O, => extent of reaction, E = (1200/32)/3 = 12.5, Let the rate be F. nSO

_{2}p = 2nH

_{2}Sp, => 0.75F – E = 2(F – 2E), => 1.25F = 3(12.5), => F = 30 moles.

12. A reactor is supplied with two steams with equal flow rates, stream-1 containing 75% SO_{2}, 25% N_{2} and stream-2 containing pure H_{2}S, if the product has 1200 grams of S, and the ratio of H2S to H_{2}O is 5 and the ratio of SO_{2} to H_{2}S is 2, what fraction of limiting reagent is converted into product?

a) 0.21

b) 0.46

c) 0.73

d) 0.83

### View Answer

_{2}S + SO

_{2}-> 3S + H

_{2}O, => extent of reaction, E = (1200/32)/3 = 12.5, Let the rate be F. nSO

_{2}p = 2nH

_{2}Sp, => 0.75F – E = 2(F – 2E), => 1.25F = 3(12.5), => F = 30 moles, => limiting reagent is H

_{2}S, => fraction of H

_{2}S converted into product = 2E/F = 2(1.25)/3 = 0.83.

13. A reactor is supplied with two steams with equal flow rates, stream-1 containing 75% SO_{2}, 25% N_{2} and stream-2 containing pure H_{2}S, if the product has 1200 grams of S, and the ratio of H_{2}S to H_{2}O is 5 and the ratio of SO_{2} to H_{2}S is 2, how many moles of water are produced?

a) 1

b) 2

c) 3

d) 4

### View Answer

_{2}S + SO

_{2}-> 3S + H

_{2}O, => extent of reaction, E = (1200/32)/3 = 12.5, Let the rate be F. nSO

_{2}p = 2nH

_{2}Sp, => 0.75F – E = 2(F – 2E), => 1.25F = 3(12.5), => F = 30 moles. 5nH

_{2}Op = nH

_{2}Sp, => 5 nH

_{2}Op = 30 – 2(12.5) = 5, => nH

_{2}Op = 1.

14. A reactor is supplied with two steams with equal flow rates, stream-1 containing 75% SO_{2}, 25% N_{2} and stream-2 containing pure H_{2}S, if the product has 1200 grams of S, and the ratio of H_{2}S to H_{2}O is 5 and the ratio of SO_{2} to H_{2}S is 2, what fraction of excess reagent is converted into product?

a) 0.23

b) 0.55

c) 0.74

d) 0.87

### View Answer

_{2}S + SO

_{2}-> 3S + H

_{2}O, => extent of reaction, E = (1200/32)/3 = 12.5, Let the rate be F. nSO

_{2}p = 2nH

_{2}Sp, => 0.75F – E = 2(F – 2E), => 1.25F = 3(12.5), => F = 30 moles. => The excess reagent is SO

_{2}, => fraction of SO

_{2}converted into product = E/0.75F = 12.5/(0.75*30) = 0.55.

15. A reactor is supplied with two steams with equal flow rates, stream-1 containing 75% SO_{2}, 25% N_{2} and stream-2 containing pure H_{2}S, if the product has 1200 grams of S, and the ratio of H_{2}S to H_{2}O is 5 and the ratio of SO_{2} to H_{2}S is 2, what is percentage of Sulfur in the product?

a) 23%

b) 47%

c) 61%

d) 84%

### View Answer

_{2}S + SO

_{2}-> 3S + H

_{2}O, => extent of reaction, E = (1200/32)/3 = 12.5, Let the rate be F. nSO

_{2}p = 2nH

_{2}Sp, => 0.75F – E = 2(F – 2E), => 1.25F = 3(12.5), => F = 30 moles. => Moles of SO

_{2}= 0.75F – E = 10, moles of H

_{2}S = F – 2E = 5, moles of N

_{2}= 7.5, moles of S = 37.5, moles of H

_{2}O = 1, => percentage of sulfur = 61%.

## Set 3

1. What is the unit of specific gravity?

a) Kg/m^{3}

b) N/m^{3}

c) m/s^{2}

d) Dimensionless

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2. What is the specific gravity of a substance with density 100 kg/m^{3} with respect to reference substance of density 100 lb/m^{3}?

a) 1.1

b) 2.2

c) 3.3

d) 4.4

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^{3}, Specific gravity = (100*2.2)/100 = 2.2.

3. If is necessary to mention the temperature at which specific gravity is calculated, because

a) Mass of the substance changes with temperature

b) Rigidity of the substance changes with temperature

c) Density of the substance changes with temperature

d) None of the mentioned

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4. What is the specific gravity of a substance with mass 10 kg and volume 2 m^{3}, with respect to the reference density 50 g/m^{3}?

a) 0.1

b) 0.2

c) 0.3

d) 0.4

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^{3}, => Specific gravity = 5/50 = 0.1.

5. What is the mass of a cone of radius 1 m and height 3 m having specific gravity 0.1? (Density of water = 1000 kg/m^{3})

a) 314.16 kg

b) 425.24 kg

c) 136.16 kg

d) 325.24 kg

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^{2}*3 = 3.1416 m

^{3}, density of cone = 0.1*1000 = 100 kg/m

^{3}, => mass of cone = 100*3.1416 = 314.16 kg.

6. API gravity is measured in,

a) Gravity meter scale

b) Hydrometer scale

c) Richer scale

d) None of the mentioned

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7. API gravity is necessary in calculation of specific gravity of petroleum products, because

a) Volume of the petroleum products changes with temperature

b) Mass of petroleum products changes with temperature

c) Potential energy of petroleum products changes with temperature

d) None of the mentioned

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8. What is the API gravity of a substance with specific gravity 1?

a) 131.5

b) 141.5

c) 10

d) 50

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9. What is the average mass of a substance with specific gravity 10, and its volume varies with time as V = t/500, from t = 2, to t = 0 seconds? (Density of water = 1000 kg/m^{3})

a) 25

b) 20

c) 40

d) 75

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^{3}, => mass of substance = 10000*t/500 = 20t, => average mass = (1/2)∫20t = 5t

^{2}= 5(2

^{2}– 0

^{2}) = 20.

10. Mass of a substance is changing with respect to its volume as m = -v^{3} + 3v^{2} -2v, what is the maximum specific gravity of the substance between v = 1 m^{3} and v = 2 m^{3}? (Density of reference substance = 0.25 kg/m^{3})

a) 1

b) 2

c) 3

d) 4

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^{2}+ 3v – 2, => Specific gravity of substance S = D/0.25 = 4(-v

^{2}+ 3v – 2), => dS/dv = 4(-2v + 3) = 0, => v = 1.5, => S is maximum at v = 1.5, => maximum specific gravity = 4(-1.5

^{2}+ 3*1.5 – 2) = 1.

11. What is the specific gravity of 10 Kg of water occupied in 10 m3 with respect to 200 g/m^{3}?

a) 0.2

b) 0.5

c) 1

d) 5

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12. What is the specific gravity of 5 Kg of water occupied in 10 m3 with respect to 500 g/m^{3}?

a) 0.5

b) 1

c) 2

d) 5

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13. What is the specific gravity of 10 Kg of water occupied in 5 m3 with respect to 100 g/m^{3}?

a) 1

b) 5

c) 10

d) 20

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14. What is the specific gravity of O2 at 27oC and 60 Pa with respect to 1 Kg/m^{3}?

a) 0.15

b) 0.28

c) 0.54

d) 0.76

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15. What is the specific gravity of N2 at 27oC and 6 Pa with respect to 0.1 Kg/m^{3}?

a) 0.16

b) 0.33

c) 0.51

d) 0.89

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## Set 4

1. For exothermic reactions, what is the heat of reaction?

a) Positive

b) Negative

c) Zero

d) Cannot Say

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2. For endothermic reactions, what is the heat of reaction?

a) Positive

b) Negative

c) Zero

d) Cannot Say

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3. Enthalpy of reactants is 15 J/Kg and enthalpy of products is 40 J/Kg, what is the heat of reaction?

a) -10 J/Kg

b) 10 J/Kg

c) -25 J/Kg

d) 25 J/Kg

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4. Enthalpy of reactants is 50 J/Kg and enthalpy of products is 25 J/Kg, what is the heat of reaction?

a) -10 J/Kg

b) 10 J/Kg

c) -25 J/Kg

d) 25 J/Kg

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5. Enthalpy of reactants is 30 J/Kg and enthalpy of products is 10 J/Kg, what is the heat of reaction?

a) -20 J/Kg

b) 20 J/Kg

c) -10 J/Kg

d) 10 J/Kg

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6. Heat of formations of A, B, C, and D, are 5 J, 10 J, 15 J, and 20 J respectively, what is the heat of reaction A + 4B -> 3C + D?

a) 10 J

b) 20 J

c) 35 J

d) 45 J

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7. Heat of formations of A, B, C, and D, are 5 J, 8 J, 2 J, and 15 J respectively, what is the heat of reaction 3A + B -> 3C + 2D?

a) 9 J

b) 10 J

c) 13 J

d) 15 J

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8. Heat of formations of A, B, C, and D, are 1 J, 2 J, 3 J, and 4 J respectively, what is the heat of reaction 3A + 4B -> 2C + D?

a) -1 J

b) 1 J

c) 3 J

d) 6 J

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9. Heat of formations of A, B, C, and D, are 2 J, 5 J, 3 J, and 10 J respectively, what is the heat of reaction 4A + 5B -> 2C + 2D?

a) -10 J

b) -7 J

c) -5 J

d) 0

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10. Heat of formations of A, B, C, and D, are 3 J, 5 J, 4 J, and 8 J respectively, what is the heat of reaction 2A + 2B -> 2C + D?

a) -5 J

b) 0

c) 5 J

d) 8 J

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11. In the reaction C + O_{2} -> CO_{2}, if the heat liberated is 10 J, what is the heat of formation of CO_{2}?

a) -10 J

b) 10 J

c) 0

d) Cannot be determined

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12. In the reaction 2H_{2} + O_{2} -> 2H_{2}O, if the heat liberated is 50 J, what is the heat of formation of H_{2}O?

a) -25 J

b) 25 J

c) -50 J

d) 50 J

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13. In the reaction 2N -> N_{2}, if the heat liberated is 6 J, what is the heat of formation of N_{2}?

a) – 6 J

b) 6 J

c) 0

d) Cannot be determined

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14. In the reaction 2C + O_{2}-> 2CO, if the heat liberated is 10 J, what is the heat of formation of CO?

a) -5 J

b) 5 J

c) -10 J

d) 10 J

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15. In the reaction C + 2H_{2} -> CH_{4}, if the heat liberated is -5 J, what is the heat of formation of CH_{4}?

a) -5J

b) 5 J

c) 0 J

d) Cannot be determined

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## Set 5

1. Which of the following remains constant in steady state system?

a) Mass

b) Energy

c) Momentum

d) Density

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2. A reaction occurs in a vessel such that its mass does not change but its temperature is increased, then the system is which of the following?

a) Steady-state

b) Unsteady-state

c) Cannot say

d) None of the mentioned

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3. A fluid enters a vessel at the rate of 10 liters/s, and leaves in two pathways one with 7 liters/s and other with 3 liters/s, then what type of flow it is?

a) Steady-state

b) Unsteady-state

c) Cannot say

d) None of the mentioned

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4. A fluid enters a vessel at the rate of 10 liters/s, and leaves in two pathways one with 5 liters/s and other with 3 liters/s, then what type of flow it is?

a) Steady-state

b) Unsteady-state

c) Cannot say

d) None of the mentioned

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5. The rate flow in and flow out in an unsteady state process are now increased by 10 Kg/s, which will be the change in accumulation?

a) 0

b) 5 Kg/s

c) 10 Kg/s

d) 20 Kg/s

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6. An unsteady-state system, with 10 liters as initial amount of water in the vessel, water flow in rate is 8 liters/ s and flow out rate is 5 liters/s, what will be the amount of water in the vessel after 10 seconds?

a) 10 liters

b) 20 liters

c) 30 liters

d) 40 liters

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7. An unsteady-state system, with 6 liters as initial amount of water in the vessel, water flow in rate is 2 liters/ s and flow out rate is 4 liters/s, what will be the amount of water in the vessel after 1 seconds?

a) 2 liters

b) 4 liters

c) 6 liters

d) 8 liters

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8. What is the final amount of fluid in the vessel if the system is in steady state?

a) Same as the initial amount

b) Twice the initial amount

c) Zero

d) None of the mentioned

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9. In what ratio 57 octane and 63 octane should be mixed to obtain 59 octane?

a) 1:1

b) 2:1

c) 3:1

d) 4:1

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10. What amount of 57 octane should be mixed with 3 liters of 63 octane to obtain 4 liters of 59 octane?

a) 1 liter

b) 2 liters

c) 2.5 liters

d) 4.5 liters

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11. An unsteady state system, the flow in rate of A is 10 mole/s, what is the flow out rate of B if the accumulation was 10 mole in 2 seconds?

a) 5 mole/s

b) 10 mole/s

c) 15 mole/s

d) 20 mole/s

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12. An unsteady state system, the flow in rate of A is 12 mole/s, what is the flow out rate of B if the accumulation was 18 mole in 3 seconds?

a) 4 mole/s

b) 6 mole/s

c) 8 mole/s

d) 9 mole/s

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13. An unsteady state system, the flow in rate of A is 5 mole/s, what is the flow out rate of B if the accumulation was 10 mole in 5 seconds?

a) 1 mole/s

b) 2 mole/s

c) 3 mole/s

d) 5 mole/s

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14. An unsteady state system, the flow in rate of A is 8 mole/s, what is the flow out rate of B if the accumulation was 6 mole in 2 seconds?

a) 1 mole/s

b) 2 mole/s

c) 3 mole/s

d) 5 mole/s

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15. An unsteady state system, the flow in rate of A is 6 mole/s, what is the flow out rate of B if the accumulation was 18 mole in 9 seconds?

a) 1 mole/s

b) 2 mole/s

c) 3 mole/s

d) 4 mole/s