# Thermochemistry and Thermodynamics Test 4

Total Questions:50 Total Time: 75 Min

Remaining:

## Questions 1 of 50

Question:The temperature of the system decreases in an

Isothermal compression

Isothermal expansion

## Questions 2 of 50

Question:For the isothermal expansion of an ideal gas

E and H increases

E increases but H decreases

H increases but E decreases

E and H are unaltered

## Questions 3 of 50

Question:Which of the following is not a state function

Internal energy

Enthalpy

Work

Entropy

## Questions 4 of 50

Question:Among them intensive property is

Mass

Volume

Surface tension

Enthalpy

## Questions 5 of 50

Question:Hess law is applicable for the determination of heat of

Reaction

Formation

Transition

All of these

## Questions 6 of 50

Question:Enthalpy for the reaction $$C + {O_2} \to C{O_2}$$ is

Positive

Negative

Zero

None

## Questions 7 of 50

Question:In which of the following $$\Delta E = \Delta H$$

$${N_2}{O_4}(g)$$ $$\leftrightarrow$$ $$2N{O_2}(g)$$

$$2S{O_2}(g) + {O_2}(g)$$ $$\leftrightarrow$$ $$2S{O_3}(g)$$

$${H_2}(g) + {I_2}(g)$$ $$\leftrightarrow$$ $$2HI(g)$$

$${H_2}(g) + \frac{1}{2}{O_2}(g)$$ $$\leftrightarrow$$ $${H_2}O(l)$$

## Questions 8 of 50

Question:In an adiabatic expansion of an ideal gas

$$W = - \Delta E$$

$$W = \Delta E$$

$$\Delta E = 0$$

$$W = 0$$

## Questions 9 of 50

Question:Enthalpy $$(H)$$ is equal to

Internal energy

Product of pressure (P) and volume (V) of gas

Internal energy +PV

Work (W) done by a system

## Questions 10 of 50

Question:$$\Delta {E^o}$$ of combustion of isobutylene is $$- X\,kJ\,mo{l^{ - 1}}$$. The value of $$\Delta {H^o}$$ is

$$= \Delta {E^o}$$

$$> \Delta {E^o}$$

$$= 0$$

$$< \Delta {E^o}$$

## Questions 11 of 50

Question:The entropy values (in JK$$^{ - {\rm{1}}}$$ mol$$^{ - {\rm{1}}}$$) of H$$_{{\rm{2}}\left( g \right)}$$ = 130.6, Cl$$_{{\rm{2}}\left( g \right)}$$ = 223.0 and HCl$$_{\left( g \right)}$$ = 186.7 at 298 K and 1 atm pressure. Then entropy change for the reaction $${H_{2(g)}} + C{l_{2(g)}} \to 2HC{l_{(g)}}$$ is

540.3

727.3

166.9

19.8

## Questions 12 of 50

Question:Which of the following is the least random state of water

Ice

Liquid water

Steam

All present same random state

## Questions 13 of 50

Question:For chemical reactions, the calculation of change in entropy is normally done

At constant pressure

At constant temperature

At constant temperature and pressure both

At constant volume

## Questions 14 of 50

Question:When the value of entropy is greater, then the ability of work

Is maximum

Is minimum

Is medium

None of these

## Questions 15 of 50

Question:An engine operating between $${150^o}C$$ and $${25^o}C$$ takes 500 J heat from a higher temperature reservoir if there are no frictional losses, then work done by engine is

147.7 J

157.75 J

165.85 J

169.95 J

## Questions 16 of 50

Question:The entropy of a perfectly crystalline solid at absolute zero is

Positive

Negative

Zero

Not definite

## Questions 17 of 50

Question:Which one of the following has $$\Delta {S^o}$$ greater than zero

$$CaO + C{O_2}(g)$$ $$\leftrightarrow$$ $$CaC{O_3}(s)$$

$$NaCl\,(aq)$$ $$\leftrightarrow$$ $$NaCl(s)$$

$$NaN{O_3}(s)$$ $$\leftrightarrow$$ $$N{a^ + }(aq) + NO_3^ - (aq)$$

$${N_2}(g) + 3{H_2}(g)$$ $$\leftrightarrow$$ $$2N{H_3}(g)$$

## Questions 18 of 50

Question:The molar heat capacity of water at constant pressure is $$75\,\,J{K^{ - 1}}mo{l^{ - 1}}$$. When 1.0 kJ of heat is supplied to 100 g of water which is free to expand the increase in temperature of water is

6.6 K

1.2 K

2.4 K

4.8 K

## Questions 19 of 50

Question:Molar heat of vaporisation of a liquid is $$6kJ\,mo{l^{ - 1}}$$. If the entropy change is $$16J\,mo{l^{ - 1}}\,{K^{ - 1}}$$, the boiling point of the liquid is

$${375^o}C$$

$$375K$$

$$273K$$

$${102^o}C$$

## Questions 20 of 50

Question:The enthalpy of fusion of ice per mole

18 kJ

8 kJ

80 kJ

6 kJ

## Questions 21 of 50

Question:If $$\Delta H_f^o$$ for $${H_2}{O_2}$$ and $${H_2}O$$ are $$- 188\,kJ/mole$$ and $$- 286\,kJ/mole$$. What will be the enthalpy change of the reaction $$2{H_2}{O_2}(l) \to 2{H_2}O(l) + {O_2}(g)$$

$$- 196\,kJ/mole$$

$$146\,kJ/mole$$

$$- 494\,kJ/mole$$

$$- 98\,kJ/mole$$

## Questions 22 of 50

Question:The heat of transition $$(\Delta {H_t})$$ of graphite into diamond would be, where $$C({\rm{graphite}}) + {O_2}(g) \to C{O_2}(g);\,\,\Delta H = x\,kJ$$ , $$C({\rm{diamond}})\, + {C_2}(g) \to C{O_2}(g);\,\,\Delta H = y\,kJ$$

$$(x + y)\,kJ\,mo{l^{ - 1}}$$

$$(x - y)\,kJ\,mo{l^{ - 1}}$$

$$(y - x)\,kJ\,mo{l^{ - 1}}$$

None of these

## Questions 23 of 50

Question:Heat of neutralisation of a strong acid by a strong base is a constant value because

Salt formed does not hydrolyse

Only $${H^ + }$$ and $$O{H^ - }$$ ions react in every case

The strong base and strong acid react completely

The strong base and strong acid react in aqueous solution

## Questions 24 of 50

Question:Heat of neutralisation of an acid by a base is highest when

Both the acid and base are weak

Both the acid and base are strong

The acid is strong and the base is weak

The acid is weak and the base is strong

## Questions 25 of 50

Question:Which is the best definition of “heat of neutralization”

The heat set free when one gram molecule of a base is neutralized by one gram molecule of an acid in dilute solution at a stated temperature

The heat absorbed when one gram molecule of an acid is neutralized by one gram molecule of a base in dilute solution at a stated temperature

The heat set free or absorbed when one gram atom of an acid is neutralized by one gram atom of a base at a stated temperature

The heat set free or absorbed when a normal solution containing one gram equivalent of an acid is neutralized by a normal solution containing one gram equivalent of a base at a stated

The heat set free when one gram equivalent of an acid is neutralized by one gram equivalent of a base in dilute solution at a stated temperature

## Questions 26 of 50

Question:The compound with negative heat of formation are known as

Endothermic compound

Exothermic compound

Heat of formation compound

None of the above

## Questions 27 of 50

Question:If $${H^ + } + O{H^ - } \to {H_2}O + 13.7\,kcal$$, then the heat of neutralization for complete neutralization of one mole of $${H_2}S{O_4}$$ by base will be

13.7 kcal

27.4 kcal

6.85 kcal

3.425 kcal

## Questions 28 of 50

Question:The enthalpy of formation of ammonia is $$- 46.0\,kJ\,mo{l^{ - 1}}$$. The enthalpy change for the reaction $$2N{H_3}(g) \to 2{N_2}(g) + 3{H_2}(g)$$ is

46.0 kJ $$mo{l^{ - 1}}$$

92.0 kJ $$mo{l^{ - 1}}$$

23.0 kJ $$mo{l^{ - 1}}$$

92.0 kJ $$mo{l^{ - 1}}$$

## Questions 29 of 50

Question:The heat of combustion of benzene determined in a bomb calorimeter is $$- 870\,kcal\,mo{l^{ - 1}}$$ at $${25^o}C$$. The value of $$\Delta E$$ for the reaction is

$$- 1740\,kcal$$

$$- 870\,kcal$$

$$- 872\,kcal$$

$$- 874\,kcal$$

## Questions 30 of 50

Question:The formation of water from $${H_2}(g)$$ and $${O_2}(g)$$ is an exothermic reaction because

The chemical energy of $${H_2}(g)$$ and $${O_2}(g)$$ is more than that of water

The chemical energy of $${H_2}(g)$$ and $${O_2}(g)$$ is less than that of water

Not dependent on energy

The temperature of $${H_2}(g)$$ and $${O_2}(g)$$ is more than that of water

## Questions 31 of 50

Question:The energy evolved is highest for which of the following reactions

$$F + {e^ - } \to {F^{ - 1}}$$

$$Cl + {e^ - } \to C{l^ - }$$

$$S + 2{e^ - } \to {S^{2 - }}$$

$$O + 2{e^ - } \to {O^{2 - }}$$

## Questions 32 of 50

Question:In the combustion of $$2.0\,gm$$ of methane $$25\,kcal$$ heat is liberated, heat of combustion of methane would be

$$100\,kcal$$

$$200\,kcal$$

$$300\,kcal$$

$$400\,kcal$$

## Questions 33 of 50

Question:Complete combustion of $$C{H_4}$$ gives

$$C{O_2} + {H_2}O$$

$$C{O_2} + {H_2}$$

$$COC{l_2}$$

$$CO + C{O_2} + {H_2}O$$

## Questions 34 of 50

Question:In the complete combustion of butanol $${C_4}{H_9}OH(l)$$, if $$\Delta H$$ is enthalpy of combustion and $$\Delta E$$ is the heat of combustion at constant volume, then

$$\Delta H < \Delta E$$

$$\Delta H = \Delta E$$

$$\Delta H > \Delta E$$

$$\Delta H,\,\Delta E$$

## Questions 35 of 50

Question:$$C + {O_2} \to C{O_2};\,\Delta H = X$$ , $$CO + \frac{1}{2}{O_2} \to C{O_2};\,\Delta H = Y$$ . Then the heat of formation of $$CO$$ is

$$X - Y$$

$$Y - 2X$$

$$X + Y$$

$$2X - Y$$

## Questions 36 of 50

Question:The values of heat of formation of $$S{O_2}$$ and $$S{O_3}$$ are $$- 298.2\,kJ$$ and $$- 98.2\,kJ$$. The heat of reaction of the following reaction will be $$S{O_2} + \frac{1}{2}{O_2} \to S{O_3}$$

$$- 200\,kJ$$

$$- 356.2\,kJ$$

$$+ 200\,kJ$$

$$- 396.2\,kJ$$

## Questions 37 of 50

Question:Given that $$C(s) + {O_2}(g) \to C{O_2}(g),\Delta H = - 394kJ$$, $$2{H_2}(g) + {O_2}(g) \to 2{H_2}O(l),\,\Delta H = 568kJ$$, $$C{H_4}(g) + 2{O_2}(g)\,\, \to \,\,C{O_2}(g) + 2{H_2}O(l)$$$$\Delta H = - 892\,kJ$$. Heat of formation of $$C{H_4}$$ is

70 kJ

71.8 kJ

244 kJ

+ 782 kJ

## Questions 38 of 50

Question:Calculate the heat of formation of $$PC{l_5}(s)$$ from the following data $$2P(s) + 3C{l_2}(g)\,\, \to \,\,2PC{l_3}(l);\,\Delta H = - 151.8\,kcal$$, $$PC{l_3}(l) + C{l_2}(g)\,\, \to \,\,PC{l_5}(s);\,\,\Delta H = - 32.8\,kcal$$

108.7 kcal

+ 108.7 kcal

184.6 kcal

+ 184.6 kcal

## Questions 39 of 50

Question:The heat of formation of methane $$C(s) + 2{H_2}(g)\, \to \,C{H_4}(g)$$ at constant pressure is 18500 cal at $${25^o}C$$. The heat of reaction at constant volume would be

17904 cal

18202 cal

18798 cal

19096 cal

## Questions 40 of 50

Question:The enthalpy of combustion of $${C_6}{H_{6(l)}}$$ is -3250 kJ. When 0.39 g of benzene is burnt excess of oxygen in an open vessel, the amount of heat evolved is

16.25 J

16.25 kJ

32.5 J

32.5 kJ

## Questions 41 of 50

Question:A cylinder of gas is assumed to contain 11.2 kg of butane $$({C_4}{H_{10}})$$. If a normal family needs 20000 kJ of energy per day. The cylinder will last: (Given that $$\Delta H$$ for combustion of butane is -2658 kJ)

20 days

25 days

26 days

24 days

## Questions 42 of 50

Question:Compounds with high heat of formation are less stable because

High temperature is required to synthesise them

Molecules of such compounds are distorted

It is difficult to synthesis them

Energy rich state leads to instability

## Questions 43 of 50

Question:What is the weight of oxygen that is required for the complete combustion of 2.8 kg of ethylene?

9.6 kg

96.0 kg

6.4 kg

2.8 kg

## Questions 44 of 50

Question:For complete neutralization of $$HCl$$ with $$NaOH,$$ the heat of neutralization is

$$+ 13.70\,kJ\,mo{l^{ - 1}}$$

$$- 13.70\,kJ\,mo{l^{ - 1}}$$

$$- 57.32\,kJ\,mo{l^{ - 1}}$$

$$+ 57.32\,kJ\,mo{l^{ - 1}}$$

## Questions 45 of 50

Question:The bond dissociation energies of gaseous $${H_2},\,C{l_2}$$ and $$HCl$$ are 104, 58 and 103 kcal respectively. The enthalpy of formation of $$HCl$$ gas would be

44 kcal

44 kcal

22 kcal

22 kcal

## Questions 46 of 50

Question:The first ionization energy for Li is 5.4 eV and electron affinity of Cl is 3.61eV. The $$\Delta H$$ (in kJ/mol) for the reaction $$Li(g) + Cl(g) \to L{i^ + } + C{l^ - }$$ is (if resulting ions do not combine with each other) $$(1\,eV = 1.6 \times {10^{ - 19}}J)$$

70

100

170

270

## Questions 47 of 50

Question:What is the free energy change $$\Delta G$$ when $$1.0\,mole$$ of water at $${100^o}C$$ and $$1\,atm$$ pressure is converted into steam at $${100^o}C$$ and $$1\,atm$$ pressure

$$540\,cal$$

$$- 9800\,cal$$

$$9800\,cal$$

$$0\,cal$$

## Questions 48 of 50

Question:$$\Delta {G^o}$$ for the reaction $$X + Y$$ $$\leftrightarrow$$ Z is -4.606 kcal . The value of equilibrium constant of the reaction at $${227^o}C$$ is $$(R = 2.0\,cal.\,mo{l^{ - 1}}{K^{ - 1}})$$

100

10

2

0.01

## Questions 49 of 50

Question:The free energy for a reaction having $$\Delta H = 31400\,ca;$$. $$\Delta S = 32\,cal\,{K^{ - 1}}\,mo{l^{ - 1}}$$ at $${1000^o}C$$ is

9336 cal

7386 cal

1936 cal

+ 9336 cal

## Questions 50 of 50

Question:The $$\Delta H$$ and $$\Delta S$$ for a reaction at one atmospheric pressure are +30.558 kJ and $$0.066\,kJ{k^{ - 1}}$$ respectively. The temperature at which the free energy change will be zero and below of this temperature the nature of reaction would be