# Thermochemistry and Thermodynamics Test 5

Total Questions:50 Total Time: 75 Min

Remaining:

## Questions 1 of 50

Question:If a refrigerator's door is opened, then we get

Room heated

Room cooled

More amount of heat is passed out

No effect on room

## Questions 2 of 50

Question:The cooling in refrigerator is due to

Reaction of the refrigerator gas

Expansion of ice

The expansion of the gas in the refrigerator

The work of the compressor

## Questions 3 of 50

Question:The first law of thermodynamics is only

The law of conservation of energy

The law of conservation of mass

The law of conservation of momentum

Both 1 and 2

## Questions 4 of 50

Question:A mixture of two moles of carbon monoxide and one mole of oxygen, in a closed vessel is ignited to convert the carbon monoxide to carbon dioxide. If $$\Delta H$$ is the enthalpy change and $$\Delta E$$ is the change in internal energy, then

$$\Delta H > \Delta E$$

$$\Delta H < \Delta E$$

$$\Delta H = \Delta E$$

The relationship depends on the capacity of the vessel

## Questions 5 of 50

Question:During an isothermal expansion of an ideal gas its

Internal energy increases

Enthalpy decreases

Enthalpy remains unaffected

Enthalpy reduces to zero

## Questions 6 of 50

Question:The work done in ergs for the reversible expansion of one mole of an ideal gas from a volume of 10 litres to 20 litres at $${25^o}C$$ is

$$2.303 \times 298 \times 0.082\,\log \,2$$

$$298 \times {10^7} \times 8.31 \times 2.303\,\log \,2$$

$$2.303 \times 298 \times 0.082\,\log \,0.5$$

$$8.31 \times {10^7} \times 298 - 2.303\,\log \,0.5$$

## Questions 7 of 50

Question:For the reaction $$C{H_3}COOH(l) + 2{O_2}(g)$$ $$\leftrightarrow$$ $$2C{O_2}(g) + 2{H_2}O(l)$$ at $${25^o}C$$ and 1 atm. pressure, $$\Delta H = - 874\,kJ.$$ Then the change in internal energy $$(\Delta E)$$ is

874 kJ

871.53 kJ

876.47 kJ

+ 874 kJ

## Questions 8 of 50

Question:In a closed insulated container, a liquid is stirred with a paddle to increase its temperature. In this process, which of the following is true

$$\Delta E = W = Q = 0$$

$$\Delta E \ne 0,\,Q = W = 0$$

$$\Delta E = W \ne 0,\,Q = 0$$

$$\Delta E = Q \ne 0,\,W = 0$$

## Questions 9 of 50

Question:One mole of an ideal gas is allowed to expand reversibly and adibatically from a temperature of $${27^o}C$$. If the work done during the process is $$3\,kJ$$, then final temperature of the gas is $$({C_V} = 20\,J/K)$$

100 K

150 K

195 K

255 K

## Questions 10 of 50

Question:Which of the following is correct regarding the internal energy of a substance

It is a state function

It increases with increase in temperature

It can be calculated by experiment

It remains unaffected with change in temperature

## Questions 11 of 50

Question:Which one of the following process is non-spontaneous

Dissolution of $$CuS{O_4}$$ in water

Reaction between $${H_2}$$ and $${O_2}$$ to form water

Water flowing down hill

Flow of electric current from low potential to high potential

## Questions 12 of 50

Question:Which of the following is zero during adiabatic expansion of the gas

$$\Delta T$$

$$\Delta S$$

$$\Delta E$$

None of these

## Questions 13 of 50

Question:Which of the following is true for the reaction $${H_2}O(l)$$$$\leftrightarrow$$$${H_2}O(g)$$ at $${100^o}C$$ and 1 atmosphere

$$\Delta E = 0$$

$$\Delta H = 0$$

$$\Delta H = \Delta E$$

$$\Delta H = T\Delta S$$

## Questions 14 of 50

Question:The enthalpy change for the transition of liquid water to steam, $$\Delta {H_{vap}} = 37.3\,kJ\,mo{l^{ - 1}}$$ at $$373\,K$$. The entropy change for the process is

$$111.9\,J\,mo{l^{ - 1}}{K^{ - 1}}$$

$$37.3\,J\,mo{l^{ - 1}}\,{K^{ - 1}}$$

$$100\,J\,mo{l^{ - 1}}{K^{ - 1}}$$

$$74.6\,J\,mo{l^{ - 1}}{K^{ - 1}}$$

## Questions 15 of 50

Question:Which of the following conditions will always lead to a non-spontaneous change

Positive $$\Delta H$$ and positive $$\Delta S$$

Negative $$\Delta H$$ and negative $$\Delta S$$

Positive $$\Delta H$$ and negative $$\Delta S$$

Negative $$\Delta H$$ and positive $$\Delta S$$

## Questions 16 of 50

Question:Following data is known about melting of a compound AB. $$\Delta H = 9.2\,kJ\,mo{l^{ - 1}}$$, $$\Delta S = 0.008\,kJ\,{K^{ - 1}}mo{l^{ - 1}}$$. Its melting point is

736 K

1050 K

$$1150\,K$$

$${1150^o}C$$

## Questions 17 of 50

Question:The work done to contract a gas in a cylinder, is 462 joules. 128 joule energy is evolved in the process. What will be the internal energy change in the process

+ 590 joules

334 joules

+ 334 joules

590 joules

## Questions 18 of 50

Question:Highest entropy is in

Hydrogen

Water

Graphite

Mercury

## Questions 19 of 50

Question:In which of the following neutralisation reactions, the heat of neutralisation will be highest

$$N{H_4}OH$$ and $$C{H_3}COOH$$

$$N{H_4}OH$$ and $$HCl$$

$$NaOH$$ and $$C{H_3}COOH$$

$$NaOH$$ and $$HCl$$

## Questions 20 of 50

Question:If $$S + {O_2} \to S{O_2};\,(\Delta H = - 298.2)$$ , $$S{O_2} + \frac{1}{2}{O_2} \to S{O_3};\,(\Delta H = - 98.2)$$, $$S{O_3} + {H_2}O \to {H_2}S{O_4};\,(\Delta H = - 130.2)$$ , $${H_2} + \frac{1}{2}{O_2} \to {H_2}O;\,(\Delta H = - 287.3)$$, then the enthalpy of formation of $${H_2}S{O_4}$$ at 298K will be

$$- 433.7\,kJ$$

$$- 650.3\,kJ$$

$$+ 320.5\,kJ$$

$$- 813.9\,kJ$$

## Questions 21 of 50

Question:Correct relationship between heat of fusion $$(\Delta {H_{fus}})$$, heat of vaporization $$(\Delta {H_{vap}})$$ and heat of sublimation $$(\Delta {H_{sub}})$$ is

$$\Delta {H_{fus}} = \Delta {H_{vap}} + \Delta {H_{sub}}$$

$$\Delta {H_{vap}} = \Delta {H_{fus}} + \Delta {H_{sub}}$$

$$\Delta {H_{sub}} = \Delta {H_{vap}} + \Delta {H_{fus}}$$

$$\Delta {H_{sub}} = \Delta {H_{vap}} - \Delta {H_{fus}}$$

## Questions 22 of 50

Question:Which of the following is an example of endothermic reaction

$${C_2}{H_2} + 2{H_2} \to {C_2}{H_6};\,\,\Delta E = - 314.0\,kJ$$

$$C + {O_2} \to C{O_2};\,\,\Delta E = - 393.5\,kJ$$

$${N_2} + {O_2} \to 2NO;\,\,\Delta E - 180.5\,kJ$$

$$2{H_2} + {O_2} \to 2{H_2}O;\,\,\Delta E + 571.8\,kJ$$

## Questions 23 of 50

Question:The standard molar heat of formation of ethane, $$C{O_2}$$ and water (l) are respectively -21.1, -94.1 and -68.3 kcal. The standard molar heat of combustion of ethane will be

372 kcal

162 kcal

240 kcal

183.5 kcal

## Questions 24 of 50

Question:Which of the following reaction is endothermic

$$CaC{O_3} \to CaO + C{O_2}$$

$$Fe + S \to FeS$$

$$NaOH + HCl \to NaCl + {H_2}O$$

$$C{H_4} + 2{O_2} \to C{O_2} + 2{H_2}O$$

## Questions 25 of 50

Question:The lowest value of heat of neutralization is obtained for

$$HCl + NaOH$$

$$C{H_3}COOH + N{H_4}OH$$

$$N{H_4}OH + HCl$$

$$NaOH + C{H_3}COOH$$

## Questions 26 of 50

Question:Heat of neutralisation for the given reaction $$NaOH + HCl \to NaCl + {H_2}O$$ is $$57.1\,kJ\,mo{l^{ - 1}}$$. What will be the heat released when $$0.25\,mole$$ of $$NaOH$$ is titrated against $$0.25\,mole$$ of $$HCl$$

$$22.5\,kJ\,mo{l^{ - 1}}$$

$$57.1\,kJ\,mo{l^{ - 1}}$$

$$14.3\,kJ\,mo{l^{ - 1}}$$

$$28.6\,kJ\,mo{l^{ - 1}}$$

## Questions 27 of 50

Question:In the reaction for the transition of carbon in the diamond form to carbon in the graphite form, $$\Delta H$$ is $$- 453.5\,cal$$. This points out that

Graphite is chemically different from diamond

Graphite is as stable as diamond

Graphite is more stable than diamond

Diamond is more stable than graphite

## Questions 28 of 50

Question:In the combustion of hydrocarbons, $$\Delta H$$ is

Negative

Zero

Positive

Undeterminate

## Questions 29 of 50

Question:If enthalpies of formation of $${C_2}{H_4}(g),\,C{O_2}(g)$$ and $${H_2}O(l)$$ at $${25^o}C$$ and $$1\,atm$$ pressure be 52, -394 and $$- 286\,kJ\,mo{l^{ - 1}}$$ respectively, the enthalpy of combustion of $${C_2}{H_4}(g)$$ will be

$$+ 1412\,kJ\,mo{l^{ - 1}}$$

$$- 1412\,kJ\,mo{l^{ - 1}}$$

$$+ 141.2\,kJ\,mo{l^{ - 1}}$$

$$- 141.2\,kJ\,mo{l^{ - 1}}$$

## Questions 30 of 50

Question:Carbon and carbon monoxide burn in oxygen to form carbon dioxide according to the following reactions $$C + {O_2} \to C{O_2};\,\Delta H = - 394\,kJ\,mo{l^{ - 1}}$$ , $$2CO + {O_2} \to 2C{O_2};\,\Delta H = - 569\,kJ\,mo{l^{ - 1}}$$ . The heat of formation of $$1\,mol$$of carbon monoxide is thus

$$- 219.0\,kJ\,mo{l^{ - 1}}$$

$$- 109.5\,kJ\,mo{l^{ - 1}}$$

$$- 175.0\,kJ\,mo{l^{ - 1}}$$

$$- 87.5\,kJ\,mo{l^{ - 1}}$$

## Questions 31 of 50

Question:Calculate the standard heat of formation of carbon disulphide $$(l)$$, given that the standard heat of combustion of carbon $$(s)$$, sulphur $$(s)$$ and carbon disulphide $$(l)$$ are $$- 393.3,\, - 293.72$$ and $$- 1108.76\,kJ\,mo{l^{ - 1}}$$ respectively

$$- 128.02\,kJ\,mo{l^{ - 1}}$$

$$+ 12.802\,kJ\,mo{l^{ - 1}}$$

$$+ 128.02\,kJ\,mo{l^{ - 1}}$$

$$- 12.802\,kJ\,mo{l^{ - 1}}$$

## Questions 32 of 50

Question:Fermentation is a reaction called

Endothermic

Exothermic

Isotemperature

Reversible

## Questions 33 of 50

Question:When $$50\,c{m^3}$$ of a strong acid is added to $$50\,c{m^3}$$ of an alkali, the temperature rises by $${5^o}C$$. If $$250\,c{m^3}$$ of each liquid are mixed, the temperature rise would be

$${5^o}C$$

$${10^o}C$$

$${25^o}C$$

$${20^o}C$$

## Questions 34 of 50

Question:$${H_2}(g) + \frac{1}{2}{O_2}(g)\,\, \to \,\,{H_2}O(l)$$; , $$\Delta H$$ at 298 K = -285.8 kJ . The molar enthalpy of vaporisation of water at 1 atm and $${25^o}C$$ is 44 kJ. The standard enthalpy of formation of 1 mole of water vapour at $${25^o}C$$ is

241.8 kJ

241.8 kJ

329.8 kJ

329.8 kJ

## Questions 35 of 50

Question:When 4 g of iron is burnt to ferric oxide at constant pressure, 29.28 kJ of heat is evolved. What is the enthalpy of formation of ferric oxide (At. Wt. of Fe = 56)

81.98 kJ

819.8 kJ

40.99 kJ

+ 819.8 kJ

## Questions 36 of 50

Question:$$C(s) + {O_2}(g)\, \to \,C{O_2};\,\,\,\,\Delta H = - 94\,kcal$$, $$CO(g) + \frac{1}{2}{O_2}(g)\, \to \,C{O_2};\,\,\,\Delta H = 135.2\,kcal$$. Then heat of formation of $$CO(g)$$ is

26.4 kcal

41.2 kcal

26.4 kcal

229.2 kcal

## Questions 37 of 50

Question:The heat of neutralization of $$HCl$$ and $$NaOH$$ is

Zero

57.3 kJ

+ 57.3 kJ

None of these

## Questions 38 of 50

Question:The following thermochemical reactions are given $$M + \frac{1}{2}{O_2}\,\, \to \,\,MO + 351.4\,kJ$$, $$X + \frac{1}{2}{O_2}\,\, \to \,\,XO + 90.8\,kJ$$. It follows that the heat of reaction for the following process $$M + XO$$ $$\leftrightarrow$$ $$MO + X$$ is given by

422.2 kJ

268.7 kJ

442.2 kJ

260.6 kJ

## Questions 39 of 50

Question:The heat evolved in the combustion of methane is given by the following equations: $$C{H_4}(g) + 2{O_2}(g)\, \to \,C{O_2}(g) + {H_2}O(l);$$$$\Delta H = - 890.3\,kJ$$. How many grams of methane would be required to produce 445.15 kJ of heat of combustion

4 g

8 g

12 g

16 g

## Questions 40 of 50

Question:Heats of combustion $$(\Delta {H^o})$$ for $$C(s),\,{H_2}(g)$$ and $$C{H_4}(g)$$ are $$- 94,\, - 68$$ and $$- 213\,kcal/mol.$$ respectively. The value of $$\Delta {H^o}$$ for the reaction, $$C(s) + 2{H_2}(g)\, \to \,C{H_4}(g)$$ is

85 kcal

111 kcal

17 kcal

170 kcal

## Questions 41 of 50

Question:If the value of $$\Delta H$$ in a reaction is positive, then the reaction is called

Exothermic

Endothermic

Polymorphic

Polytropic

## Questions 42 of 50

Question:The heat of combustion of carbon to $$C{O_2}$$ is $$- 393.5\,kJ/mol$$. The heat released upon formation of 35.2 g of $$C{O_2}$$ from carbon and oxygen gas is

$$+ \,315\,kJ$$

$$- \,31.5\,kJ$$

$$- 315\,kJ$$

$$+ 31.5\,kJ$$

## Questions 43 of 50

Question:Which of the following equations correctly represents the standard heat of formation $$(\Delta H_f^o)$$ of methane

$$C$$(diamond) $$+ 4{H_{(g)}} \to C{H_{4\,(g)}}$$

$$C$$ (diamond) $$+ 2{H_{2\,(g)}} \to C{H_{4\,(g)}}$$

$$C$$ (graphite) $$+ 2{H_{2\,(g)}} \to C{H_{4\,(g)}}$$

$$C$$ (graphite) $$+ 4{H_{(g)}} \to C{H_{4\,(g)\,}}$$

## Questions 44 of 50

Question:If the heat of formation of $$C{O_2}$$ is$$- 393\,kJ$$. The amount of heat evolved in the formation of 0.156 kg of $$C{O_2}$$ is

$$- 1357.9\,\,kJ$$

$$- 1275.9\,kJ$$

$$- 1572.0\,kJ$$

$$- 1165.5\,kJ$$

## Questions 45 of 50

Question:Given that $$C(g) + 4H(g)\, \to \,C{H_4}(g);\,\Delta H = - 166\,kJ$$. The bond energy $$C - H$$ will be

208 kJ/mole

41.6 kJ/mole

832 kJ/mole

None of these

## Questions 46 of 50

Question:The $$H - H$$ bond energy is 430 kJ $$mol$$ and $$Cl - Cl$$ bond energy is $$240\,kJ\,mo{l^{ - 1}}.\,\,\Delta H$$ for $$HCl$$ is $$- 90\,kJ$$. The $$H - Cl$$ bond energy is about

$$180\,kJ\,mo{l^{ - 1}}$$

$$360\,kJ\,mo{l^{ - 1}}$$

$$213\,kJ\,mo{l^{ - 1}}$$

$$425\,kJ\,mo{l^{ - 1}}$$

## Questions 47 of 50

Question:If enthalpies of methane and ethane are respectively 320 and 360 calories then the bond energy of $$C - C$$ bond is

80 calories

40 calories

60 calories

120 calories

## Questions 48 of 50

Question:The standard enthalpy of the decomposition of $${N_2}{O_4}$$ to $$N{O_2}$$ is 58.04 kJ and standard entropy of this reaction is 176.7 J/K. The standard free energy change for this reaction at $${25^o}C$$ is

539 kJ

539 kJ

5.39 kJ

5.39 kJ

## Questions 49 of 50

Question:Spontaneity of a chemical reaction is decided by the negative change in

Internal energy

Enthalpy

Entropy

Free energy

## Questions 50 of 50

Question:For a reaction at $${25^o}C$$ enthalpy change and entropy changes are $$- 11.7 \times {10^3}J\,mo{l^{ - 1}}$$ and $$- 105\,J\,mo{l^{ - 1}}{K^{ - 1}}$$ respectively. What is the Gibbs free energy