Chem Brain

Question#1

68 kJ

65 kJ

57.3 k

50 kJ

Please select an option

Question#2

– 1802 kJ

+1802 kJ

– 800 kJ

+ 228 kJ

Please select an option

Question#3

– 6.2 kJ

– 37.4 kJ

– 35.5 kJ

– 20.0 kJ

Please select an option

Question#4

– 2

2

– 22

– 16

Please select an option

Question#5

The enthalpy of combustion of methane at 25oC is 890 kJ . The heat liberated when 3.2 g of methane is burnt in air is [KCET 2004]

445 kJ

278 kJ

-890 kJ

178 kJ

Please select an option

Question#6

The enthalpies of combustion of carbon and carbon monodie are – 393.5 and –283 kJ mol^–1 respectivley. The enthalpy of formation of carbon monoxide per mole is [AIEEE 2004]

-676.5 kJ

676.5 kJ

110.5 kJ

-110.5 kJ

Please select an option

Question#7

Which of the following pairs has heat of neutralisation equal to 13.7 Kcals [DCE 2003]

HCl, NH₄OH

HNO₃ , KOH

NaOH,CH₃COOH

H₂SO₄ , NH₄OH

Please select an option

Question#8

If the heat of formation of CO₂ is -393 kJ . The amount of heat evolved in the formation of 0.156 kg of CO₂ is [MH CET 2004]

-1357.9 kJ

-1275.9 kJ

-1572.0 kJ

-1165.5 kJ

Please select an option

Question#9

Please select an option

Question#10

The heat of combustion of carbon to CO₂ is -393.5 kJ / mol . The heat released upon formation of 35.2 g of CO₂ from carbon and oxygen gas is [UPSEAT 2004]

+ 315 kJ

- 31.5 kJ

-315 kJ

+31.5 kJ

Please select an option

Question#11

For complete neutralization of HCl with NaOH, the heat of neutralization is [MP PET 2003]

+13.70 kJ mol^-1

-13.70 kJ mol^-1

-57.32 kJ mol^-1

+57.32 kJ mol^-1

Please select an option

Question#12

What is the weight of oxygen that is required for the complete combustion of 2.8 kg of ethylene? [BVP 2003]

9.6 kg

96.0 kg

6.4 kg

2.8 kg

Please select an option

Question#13

– 3.8

– 1.9

+ 3.8

+ 1.9

Please select an option

Question#14

Enthalpy change for a reaction does not depend upon [AIEEE 2003]

The physical states of reactants and products

Use of different reactants for the same product

The nature of intermediate reaction steps

The differences in initial or final temperatures of involved substances

Please select an option

Question#15

Please select an option

Question#16

One gram sample of NH₄ NO₃ is decomposed in a bomb calorimeter. The temperature of the calorimeter increases by 6.12 K the heat capacity of the system is 1.23 kJ/g/deg. What is the molar heat of decomposition for NH₄ NO₃ [AIIMS 2003]

– 7.53 kJ/mol

– 398.1 kJ/mol

– 16.1 kJ/mol

– 602 kJ/mol

Please select an option

Question#17

Please select an option

Question#18

1 mole of conc. HCl requires X moles of dilute NaOH for neutralisation and 1 mole of concentrate H₂SO₄ requires Y moles of small dilute NaOH then which of the following reaction is true [MH CET 2001]

Y = 1/2 X

X= 1/2 Y

X = 2Y

None of these

Please select an option

Question#19

On combustion, carbon forms two oxides CO and CO₂, Heat of formation of CO₂ gas is 94.3 kcal and that of CO is 26.0 kcal. Heat of combustion of carbon is [JIPMER 2002]

26.0 kcal

– 94.3 kcal

68.3 kcal

– 120.3 kcal

Please select an option

Question#20

Which of the following reactions is not exothermic [MP PET 2002]

Please select an option

Question#21

If a mole of H₂ molecule is heated to high temperature the following reaction takes place [Kerala (Med.) 2002]

Please select an option

Question#22

The heat of neutralisation will be highest in [MP PMT 2002]

NH₄OH and CH₃COOH

NH₄OH and HCl

KOH and CH₃COOH

KOH and HCl

Please select an option

Question#23

Enthalpy of neutralisation of NH₄OH and HCl , is numerically [JIPMER 2002; Kurukshetra CEE 2002]

57.1 kJ mol^-1

<57.1 kJ mol^-1

>57.1 kJ mol^-1

Zero

Please select an option

Question#24

Exothermic

Endothermic

Polymorphic

Polytropic

Please select an option

Question#25

– 85 kcal

– 111 kcal

– 17 kcal

– 170 kcal

Please select an option

Question#26

4 g

8 g

12 g

16 g

Please select an option

Question#27

Compounds with high heat of formation are less stable because [KCET 2002]

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

Please select an option

Question#28

20 days

25 days

26 days

24 days

Please select an option

Question#29

When the aqueous solution of 0.5 mole HNO₃ is mixed with the 0.3 mole of OH^- solution, then what will be the liberated heat (Enthalpy of neutralization is = 57.1 kJ) [Kerala CET 2005]

28.5 kJ

17.1 kJ

45.7 kJ

1.7 kJ

2.85 kJ

Please select an option

Question#30

11 kcal

32 kcal

44 kcal

22 kcal

Please select an option

Question#31

A system is changed from state A to state B by one path and from B to A another path. If E₁ and E₂ are the corresponding changes in internal energy, then [Pb. PMT 2001]

E₁ + E₂ = -ve

E₁ + E₂ = +ve

E₁ + E₂ = 0

None of these

Please select an option

Question#32

Heat of neutralization of strong acid and weak base is [UPSEAT 2001]

57.1 kJ mol^-1

13.7 kJ mol^-1

Less than 13.7 kJ mol^-1

More than 13.7 kJ mol^-1

Please select an option

Question#33

47.3 kcal

20.0 kcal

45.9 kcal

– 47.3 kcal

Please select an option

Question#34

0

3/2

-3/2

1/2

Please select an option

Question#35

In order to decompose 9 g water 142.5 kJ heat is required. Hence the enthalpy of formation of water is [KCET 2001]

– 142.5 kJ

+ 142.5 kJ

– 285 kJ

+ 285 kJ

Please select an option

Question#36

For exothermic reaction, the equilibrium constant [JIPMER 2001]

Increases with increase of P

Decreases with increase of P

Increases with increase of temperature

Decreases with increase of temperature

Please select an option

Question#37

The values of for the combustion of ethene and ethyne are – 341.1 and – 310.0kcal respectively. Which of the following is a better fuel

C₂H₂

C₂H₄

Both of these

None of these

Please select an option

Question#38

196 kJ

– 196 kJ

984 kJ

– 984 kJ

Please select an option

Question#39

If the heat of combustion of carbon monoxide at constant volume and at 17^oC is – 283.3 kJ, then its heat of combustion at constant pressure ( R= 8.314 degree^-1 Jmol^-1) [CPMT 2001]

– 284.5 kJ

284.5 kJ

384.5 kJ

– 384.5 kJ

Please select an option

Question#40

422.2 kJ

268.7 kJ

– 442.2 kJ

260.6 kJ

Please select an option

Question#41

The heat of neutralization of HCl and NaOH is [MP PET 2001]

Zero

– 57.3 kJ

+ 57.3 kJ

None of these

Please select an option

Question#42

– 26.4 kcal

41.2 kcal

26.4 kcal

– 229.2 kcal

Please select an option

Question#43

The enthalpy of combustion of C₆H_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 [KCET 2000; AFMC 2000; DCE 2000]

16.25 J

16.25 kJ

32.5 J

32.5 kJ

Please select an option

Question#44

17904 cal

18202 cal

18798 cal

19096 cal

Please select an option

Question#45

Heat of combustion

Heat of neutralisation

Heat of solution

None of these

Please select an option

Question#46

Which of the following compounds will absorb the maximum quantity of heat when dissolved in the same amount of water ? The heats of solution of these compounds at 25^oC in kJ/mole of each solute is given in brackets [AMU (Engg.) 2000]

Please select an option

Question#47

524.1

41.2

– 262.5

– 41.2

Please select an option

Question#48

– 108 kcal

– 196 kcal

– 98 kcal

54 kcal

Please select an option

Question#49

122.25 kcal mol^-1

390.5 kcal mol^-1

1562.0 kcal mol^-1

586.75 kcal mol^-1

Please select an option

Question#50

7.3 kcal

More than 7.3

Zero

None of these

Please select an option

Question#51

Heat of neutralization of the acid-base reaction is 57.32 kJ for [JIPMER 2000]

HNO₃ + LiOH

HCOOH + KOH

HCl + NH ₄OH

CH ₃COOH + NaOH

Please select an option

Question#52

+ 5.3 kJ/mol

+ 6.2 kJ/mol

+ 8.2 kJ/mol

+ 9.3 kJ/mol

Please select an option

Question#53

+ 97 kJ

+ 194 kJ

– 194 kJ

– 97 kJ

Please select an option

Question#54

2.1 g of Fe combines with S evolving 3.77 kJ. The heat of formation of FeS in kJ/mol is [AMU (Engg.) 1999]

– 1.79

– 100.5

– 3.77

None of these

Please select an option

Question#55

When a strong acid, strong base or their salt are dissolved in water, they are completely ionised. If a strong acid is added to a strong base, H⁺ ions from the former combine with OH^- ions of the latter forming water. The formation of each water molecule liberates a certain quantity of energy and the reaction is exothermic. The heat liberated when one mole of water is formed by combining hydrochloric acid and sodium hydroxide is 13.7 kcal. The heat liberated when one mole of water is formed by combining sulphuric acid and sodium hydroxide is [AMU (Engg.) 1999]

25.5 kcal

8.5 kcal

13.7 kcal

34 kcal

Please select an option

Question#56

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) [AIIMS 1999]

– 81.98 kJ

– 819.8 kJ

– 40.99 kJ

+ 819.8 kJ

Please select an option

Question#57

The molar enthalpy of vaporisation of water at 1 atm and 25^oC is 44 kJ. The standard enthalpy of formation of 1 mole of water vapour at 25^oC is

– 241.8 kJ

241.8 kJ

329.8 kJ

–329.8 k

Please select an option

Question#58

When 50 cm³ of a strong acid is added to 50 cm³ of an alkali, the temperature rises by 5^oC . If 250 cm³ of each liquid are mixed, the temperature rise would be [KCET 1999]

5^oC

10^oC

25^oC

20^oC

Please select an option

Question#59

– 108.7 kcal

+ 108.7 kcal

– 184.6 kcal

+ 184.6 kcal

Please select an option

Question#60

– 70 kJ

71.8 kJ

– 244 kJ

+ 782 kJ

Please select an option

Question#61

0.064 kcal

0.64 kcal

6.4 kcal

64 kcal

Please select an option

Question#62

Ozone is prepared by passing silent electric discharge through oxygen. In this reaction [AFMC 1998]

Energy is given out

Energy is absorbed

Oxygen is loaded with energy

Oxygen is dissociated into atoms

Please select an option

Question#63

When 0.5g of sulphur is burnt to SO₂ ,4.6 kJ of heat is liberated. What is the enthalpy of formation of sulphur dioxide [KCET 1998; AFMC 2001]

+ 147.2 kJ

– 147.2 kJ

– 294.4 kJ

+ 294.4 kJ

Please select an option

Question#64

The neutralisation of a strong acid by a strong base liberates an amount of energy per mole of H⁺ that [BHU 1998]

Depends upon which acid and base are involved

Depends upon the temperature at which the reaction takes place

Depends upon which catalyst is used

Is always the same

Please select an option

Question#65

Equal volumes of methanoic acid and sodium hydroxide are mixed. If x is the heat of formation of water, then heat evolved on neutralisation is [BHU 1998]

More than x

Equal to x

Twice of x

Less than x

Please select an option

Question#66

890.4 kJ mol^-1

-298.8 kJ mol^-1

-74.7 kJ mol^-1

-107.7 kJ mol^-1

Please select an option

Question#67

2x - y

2x + y

x + y

2x / y

Please select an option

Question#68

The enthalpy change of a reaction does not depend on [AIIMS 1997]

The state of reactants and products

Nature of reactants and products

Different intermediate reaction

Initial and final enthalpy change of a reaction

Please select an option

Question#69

29.4 kJ

– 11.8 k

– 20.6 kJ

– 29.4 kJ

Please select an option

Question#70

20.8 kcal

19.8 kcal

18.8 kcal

20.2 kcal

Please select an option

Question#71

8 gm of CH₄ is completely burnt in air. The number of moles of water produced are [Orissa JEE 1997]

0.5

1

2

18

Please select an option

Question#72

Fermentation is a reaction called [RPMT 1997]

Endothermic

Exothermic

Isotemperature

Reversible

Please select an option

Question#73

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 mol^-1 respectively [Roorkee 1989; BHU 1997]

-128.02 kJ mol^-1

+12.802 kJ mol^-1

+128.02 kJ mol^-1

-12.802 kJ mol^-1

Please select an option

Question#74

-200 kJ

-356.2kJ

+200 kJ

-396.2kJ

Please select an option

Question#75

X - Y

Y - 2X

X + Y

2X - Y

Please select an option

Question#76

Please select an option

Question#77

Standard molar enthalpy of formation of CO₂ is equal to [IIT JEE 1997; BHU 2001]

Zero

The standard molar enthalpy of combustion of gaseous carbon

The sum of standard molar enthalpies of formation of CO and O₂

The standard molar enthalpy of combustion of carbon (graphite)

Please select an option

Question#78

– 16 kJ

+ 66 kJ

+ 16 kJ

– 66 kJ

Please select an option

Question#79

2.2016 gm of acetaldehyde produced 13.95kcal of heat on combustion in O₂ . Calculate the heat of combustion of CH₃CHO [Bihar CEE 1995]

279 kcal

972 kcal

27.9 kcal

2.79 kcal

Please select an option

Question#80

Zero

Positive

Negative

Constant

Please select an option

Question#81

The heat of reaction at constant pressure is given by [MP PMT 1997]

E_P - E_R

E_R - E_P

H_P - H_R

H_R- H_P

Please select an option

Question#82

Enthalpy of formation of HF and HCl are -161kJ and -92kJ respectively. Which of the following statements is incorrect [KCET 2003]

HCl is more stable than HF

HF and HCl are exothermic compounds

The affinity of fluorine to hydrogen is greater than the affinity of chlorine to hydrogen

HF is more stable than HCl

Please select an option

Question#83

+ 3172.8 kJ

– 1549.2 kJ

– 3172.8 kJ

– 3264.6 kJ

Please select an option

Question#84

Heat of vaporization

Heat of solution

Heat of fusion

Heat of formation

Please select an option

Question#85

Positive

Negative

Zero

Both positive or negative

Please select an option

Question#86

When water is added to quick lime, the reaction is [MP PMT 1995]

Exothermic

Endothermic

Explosive

None of these

Please select an option

Question#87

44 kcal

44000 kcal

22 kcal

11 kcal

Please select an option

Question#88

-219.0 kJ mol-1

-109.5 kJ mol-1

-175.0 kJ mol-1

-87.5 kJ mol-1

Please select an option

Question#89

+1412 kJ mol^-1

-1412 kJ mol^-1

+141.2 kJ mol^-1

-141.2 kJ mol^-1

Please select an option

Question#90

Complete combustion of CH 4 gives [BHU 1995]

CO₂ + H₂O

CO₂ + H₂

COCl₂

CO + CO₂ + H₂O

Please select an option

Question#91

In the combustion of 2.0 gm of methane 25kcal heat is liberated, the heat of combustion of methane would be [MP PMT 1994]

100kcal

200kcal

300kcal

400kcal

Please select an option

Question#92

The energy evolved is highest for which of the following reactions[MP PET 1994]

Please select an option

Question#93

For an exothermic reaction [MP PET 1994; Manipal MEE 1995]

H of the products is less than H of the reactants

H of the products is more than H of the reactants

H of the products is equal to H of the reactants

Please select an option

Question#94

Less than in the second case by 1.89kJ

More than in the second case by 1.89kJ

Less than in the second case by 11.34 kJ

More than in the second case by 0.945kJ

Please select an option

Question#95

Heat of transition is the heat evolved or absorbed when a substance is converted from [KCET 1984]

Solid to liquid

Solid to vapour

Liquid to vapour

One allotropic form to another allotropic form

Please select an option

Question#96

-393kJ

-655kJ

+393kJ

+655kJ

Please select an option

Question#97

21.16kJ

-21.10kJ

-13.62kJ

13.6 kJ

Please select an option

Question#98

In which of the following reactions does the heat change represent the heat of formation of water [EAMCET 1991]

Please select an option

Question#99

[IIT JEE (Screening) 1992]

Please select an option

Question#100

Which of the following values of heat of formation indicates that the product is least stable [MP PMT 1991]

-94 kcal

-231.6 kcal

+21.4 kcal

+64.8 kcal

Please select an option

Question#101

-1.5 kJ

+1.5 kJ

+3.0 kJ

-3.0 kJ

Please select an option

Question#102

–7.43

+ 3.72

–3.72

+ 7.43

Please select an option

Question#103

10.0

– 6.0

– 12.0

– 14.0

Please select an option

Question#104

Negative

Zero

Positive

Undeterminate

Please select an option

Question#105

Graphite is chemically different from diamond

Graphite is as stable as diamond

Graphite is more stable than diamond

Diamond is more stable than graphite

Please select an option

Question#106

The formation of water from H₂ (g) and O₂(g) is an exothermic reaction because [MP PMT/PET 1988]

The chemical energy of H₂ (g) and O₂(g) is more than that of water

The chemical energy of H₂ (g) and O₂(g) is less than that of water

Not dependent on energy

The temperature of H₂ (g) and O₂(g) is more than that of water

Please select an option

Question#107

-1740kcal

-870kcal

-872kcal

-874 kcal

Please select an option

Question#108

46.0 kJ mol^-1

92.0 kJ mol^-1

-23.0 kJ mol^-1

-92.0 kJ mol^-1

Please select an option

Question#109

Which of the following reactions can be used to define the heat of formation of CO₂(g) [MP PMT 1989; MH CET 2001]

Please select an option

Question#110

-68.39 + 48 -14

-68.39 - 48 +14

68.39 - 48 +14

68.39 + 48 +14

Please select an option

Question#111

Which of the following statements is correct about heat of combustion [MADT Bihar 1982]

It may be exothermic in some cases and endothermic in other cases

It is applicable to gaseous substances only

It is always an exothermic reaction

Its value does not change with temperature

Please select an option

Question#112

One of the phenomena which cannot be described as combustion is [EAMCET 1979]

Oxidation of coal in air

Burning of magnesium in nitrogen

Reaction of antimony in chlorine

Lighting of an electric lamp

Please select an option

Question#113

Which of the following is an endothermic reaction [EAMCET 1980; MP PMT 1980; IIT JEE 1989; JIPMER 2002]

Please select an option

Question#114

A reaction that takes place with the absorption of energy is [EAMCET 1977]

Burning of a candle

Rusting of iron

Electrolysis of water

Digestion of food

Please select an option

Question#115

If a chemical reaction is accompanied by the evolution of heat, it is [BHU 1979]

Catalytic

Photochemical

Endothermic

Exothermic

Please select an option

Question#116

The heat of combustion of CH_4(g), C_(graphite) , and H_2(g) is 20kcal,-40kcal and -10kcal respectively. The heat of formation of methane is [EAMCET 1998]

-4.0 kcal

+40kcal

-80kcal

+80kcal

Please select an option

Question#117

Is always negative

Is always positive

May be negative or positive

Is zero

Please select an option

Question#118

All reactions with chemical dissociation are [MP PMT 1990]

Reversible

Reversible and endothermic

Exothermic

Reversible or irreversible and endothermic or exothermic

Please select an option

Question#119

12.4 kcal

- 12.4 kcal

– 6.20 kcal

6.20 kcal

Please select an option

Question#120

22.5 kJ mol^-1

57.1 kJ mol^-1

14.3 kJ mol^-1

28.6 kJ mol^-1

Please select an option

Question#121

The lowest value of heat of neutralization is obtained for [KCET 1988; MP PMT 1990]

HCl + NaOH

CH₃COOH + NH₄OH

NH₄OH + HCl

NaOH + CH₃COOH

Please select an option

Question#122

13.7 kcal

27.4 kcal

6.85 kcal

3.425 kcal

Please select an option

Question#123

The compound with negative heat of formation are known as[DPMT 1981]

Endothermic compound

Exothermic compound

Heat of formation compound

None of the above

Please select an option

Question#124

Which is the best definition of “heat of neutralization” [CMC Vellore 1991]

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 temperature

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

Please select an option

Question#125

Enthalpy of a compound is equal to its [CMC Vellore 1991]

Heat of combustion

Heat of formation

Heat of reaction

Heat of solution

Please select an option

Question#126

A solution of 500ml of 0.2 M KOH and 500ml of 0.2 M HCl is mixed and stirred; the rise in temperature is T₁ . The experiment is repeated using 250ml each of solution, the temperature raised is T₂ . Which of the following is true [EAMCET 1987; MP PET 1994]

T₁ = T₂

T₁ = 2T₂

T₁ = 4T₂

T₂ =9T₁

Please select an option

Question#127

The heat of neutralisation of a strong acid and a strong alkali is 57.0 kJ mol^-1 . The heat released when 0.5mole of HNO₃ solution is mixed with 0.2 mole of KOH is [KCET 1991; AIIMS 2002; AMU (Engg.) 2002]

57.0 kJ

11.4 kJ

28.5 kJ

34.9 kJ

Please select an option

Question#128

The heat of combustion of carbon is –94 kcal at 1 atm pressure. The intrinsic energy of CO₂ is

+94 kcal

-94 kcal

+47kcal

-47 kcal

Please select an option

Question#129

Which of the following fuels will have the highest calorific value (kJ/kg) [MP PMT 1990]

Charcoal

Kerosene

Wood

Dung

Please select an option

Question#130

The heat of formation of H₂O (l) is – 68.0 kcal, the heat of formation of H₂O (g) is likely to be

– 68.0 kcal

– 67.4 kcal

80.0 kcal

– 58.3 kcal

Please select an option

Question#131

The heats of combustion of rhombic and monoclinic sulphur are respectively 70960 and 71030 calories. What will be the heat of conversion of rhombic sulphur to monoclinic [MP PMT/PET 1988]

70960 calories

71030 calories

– 70 calories

+ 70 calories

Please select an option

Question#132

Heat of formation

Heat of reaction

Heat of combustion

Heat of solution

Please select an option

Question#133

Heat of reaction

Heat of formation

Heat of vaporisation

None of the above

Please select an option

Question#134

Heat of combustion of a substance [CPMT 1987, 96; AFMC 1992]

Is always positive

Is always negative

Is equal to heat of formation

Nothing can be said without reaction

Please select an option

Question#135

Heat of formation

Heat of combustion

Heat of neutralization

Heat of reaction

Please select an option

Question#136

Which of the following reaction is endothermic [AFMC 1988]

Please select an option

Question#137

. The standard molar heat of formation of ethane, CO₂ and water (l) are respectively – 21.1, – 94.1 and – 68.3 kcal. The standard molar heat of combustion of ethane will be [IIT JEE 1986; DPMT 2005]

– 372 kcal

162 kcal

–240 kcal

183.5 kcal

Please select an option

Question#138

Heat of neutralisation of an acid by a base is highest when [KCET 1985]

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

Please select an option

Question#139

Heat of neutralisation of a strong acid by a strong base is a constant value because [KCET 1984]

Salt formed does not hydrolyse

Only H⁺ and OH^_ions react in every case

The strong base and strong acid react completely

The strong base and strong acid react in aqueous solution

Please select an option

Question#140

The heat of reaction does not depend upon

Temperature of the reaction

Physical state of reactants and products

Whether the reaction is carried out at constant pressure or at constant volume

The method by which the final products are obtained from the reactants

Please select an option

Question#141

Heat of formation of CO₂(g) HO₂(l) and CH₄(g) are – 94.0, – 68.4, and – 17.9 kcal respectively. The heat of combustion of methane is

– 212.9 kcal

– 136.8 kcal

– 304.3 kcal

– 105.2 kcal

Please select an option

Question#142

CH₄

C₂H₆

C₂H₄

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Question#143

Heat of neutralisation of NH₄OH and HCl is [EAMCET 1980; Roorkee 1990; MP PMT 1994]

13.7 kcal

>13.7 kcal

<13.7 kcal

None of the above

Please select an option

Question#144

The enthalpy of combustion at 25°C of H2 , cyclohexane (C₆H₁₂) and cyclohexene (C₆H₁₀) are –241, –3920 and –800 KJ / mole respectively. The heat of hydrogenation of cyclohexene is [BHU 2005]

– 121 KJ / mole

+ 121 KJ / mole

– 242 KJ / mole

+ 242 KJ / mole

Please select an option

Question#145

The heat of formations of CO(g) and ( ) CO2 g are -26.4 kcal and -94.0 kcal respectively. The heat of combustion of carbon monoxide will be [MP PET/PMT 1988; EAMCET 1993]

+26.4 kcal

-67.6 kcal

-120.6kcal

+52.8 kcal

Please select an option

Question#146

The mutual heat of neutralization of 40 gm of NaOH and 60 gm CH₃COOH will be [MP PET/PMT 1988]

56.1 kcal

Less than 56.1 kcal

More than 56.1 kcal

13.7 kcal

Please select an option

Question#147

Is negative

Is positive

Is zero

Depends on temperature

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Question#148

The enthalpy of neutralization is about 57.3 kJ for the pair

HCl and NH₄OH

NH₄OH and HNO₃

HCl and NaOH

CH₃COOH and NaOH

Please select an option

Question#149

Enthalpy of combination

Enthalpy of reaction

Enthalpy of formation

Enthalpy of fusion

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Question#150

-1802kJ

+1802kJ

-800kJ

+228 kJ

Please select an option

Question#151

If the enthalpy of B is greater than of A, the reaction A -> B is [MP PMT 1997]

Endothermic

Exothermic

Instantaneous

Spontaneous

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Question#152

Which of the following is an example of endothermic reaction[MP PMT 1980]

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Question#153

Please select an option

Question#154

(x + y) kJ mol^-1

(x - y) kJ mol^-1

(y - x) kJ mol^-1

None of these

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Question#155

-196kJ /mole

146kJ /mole

-494 kJ /mole

-98 kJ /mole

Please select an option

Question#156

_f (298 K) of methanol is given by the chemical equation[AIIMS 2005]

Please select an option

Question#157

Less than -57.33 kJ mol^-1

-57.33 kJ mol^-1

Greater than -57.33 kJ mol^-1

57.33 kJ mol^-1

Please select an option

Question#158

Which of the following statement is correct [NCERT 1978]

The heat of neutralization of strong acid and strong base is always the same

The enthalpy of fusion is negative

Please select an option

Question#159

An endothermic reaction is one in which [MNR 1980; NCERT 1976]

Heat is converted into electricity

Heat is absorbed

Heat is evolved

Heat is converted into mechanical work

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Question#160

An exothermic reaction is one which [NCERT 1977; MP PMT 1990]

Takes place only on heating

Is accompanied by a flame

Is accompanied by a absorption of heat

Is accompanied by evolution of heat

Please select an option

Question#161

Evaporation of water is [CPMT 1973; DPMT 1982; MP PMT 1989; MP PET 1999]

An endothermic change

An exothermic change

A process where no heat change occurs

A process accompanied by chemical reaction

Please select an option

Question#162

The following is (are) endothermic reaction [IIT JEE 1999]

Combustion of methane

Decomposition of water

Dehydrogenation of ethane to ethylene

Conversion of graphite to diamond

Please select an option

Question#163

– 393.7 kJ

+ 393.7 kJ

– 172.7 kJ

+ 172.7 k

Please select an option

Question#164

816.15 kJ

1632.3 kJ

6528.2 kJ

2448.45 kJ

Please select an option

Question#165

An exothermic reaction is one in which the reacting substances[CPMT 1974, 79; Bihar MEE 1982; KCET 1992; JIPMER 2001]

Have more energy than the products

Have less energy than the products

Are at a higher temperature than the product

None of the above

Please select an option

Question#166

The molar neutralization heat for KOH and HNO₃ as compared to molar neutralization heat of NaOH and HCl [MP PMT 1989]

Less

More

Equal

Depends on pressure

Please select an option

Question#167

From Kirchhoff's equation which factor affects the heat of reaction[MP PMT 1990]

Pressure

Temperature

Volume

Molecularity

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Question#168

-433.7 kJ

+650.3 kJ

+320.5 kJ

-813.9 kJ

Please select an option

Question#169

In which of the following neutralisation reactions, the heat of neutralisation will be highest [MP PMT 1989, 91; AIIMS 1999]

NH₄OH and CH₃COOH

NH₄OH and HCl

NaOH and CH₃COOH

NaOH and HCl

Please select an option

Question#170

The enthalpy of fusion of ice per mole

18 kJ

8 kJ

80 kJ

6 kJ

Please select an option

Question#171

375^oC

375K

273K

120^oC

Please select an option

Question#172

47.3 kcal

20.0 kcal

45.9 kcal

– 47.3 kcal

Please select an option

Question#173

What is the reason of energy change in a chemical reaction? MDCAT2023

Bond formation

Bond breakage

Bond formation and bond breakage

Ionic bonds

Please select an option

Question#174

\( \frac{1}{2} H_2 \rightarrow H \ \Delta H =+218kJmol^{-1} \)

In this reaction \( \Delta H \) will be called MDCAT2016

\( \Delta H_{at} \)

\( \Delta H_{sol} \)

\( \Delta H_n \)

\( \Delta H_f \)

Please select an option

Question#175

The equation represents standard enthalpy of atomization of hydrogen is MDCAT2015

\( \frac{1}{2} H_2O \rightarrow H_2 + \frac{1}{2}O \ \Delta H =+218kJmol^{-1} \)

\( \frac{1}{2} H_2O \rightarrow H_2 + \frac{1}{2}O \ \Delta H =-218kJmol^{-1} \)

\( \frac{1}{2} H_2 \rightarrow H \ \Delta H =+218kJmol^{-1} \)

\( \frac{1}{2} H_2 \rightarrow H \ \Delta H =-218kJmol^{-1} \)

Please select an option

Question#176

Heat of formation( \( \Delta H_f \) )for CO₂ is MDCAT2013

-390KJ/mol

+394KJ/mol

-394KJ/mol

-290KJ/mol

Please select an option

Question#177

The absolute enthalphy of neutralisation of the reaction
MgO(s) + HCl(aq) → MgCl(aq) + H₂O(l) will be
[CBSE PMT 2005]

Less than -57.33kJ mol^-1

-57.33Kjmol^-1

Greater than -57.33kJ mol^-1

+57.33kJ mol^-1

Please select an option

Question#178

The following is (are) endothermic reaction [IIT JEE 1999]

Combustion of methane

Decomposition of water

Dehydrogenation of ethane to ethylene

Conversion of graphite to diamond

Please select an option

Question#179

Thermochemical reactions

C (graphite) + 1/2O₂ →CO(g) ΔH= -110.5 KJ

CO(g) +1/2 O₂(g) →CO₂(g); ΔH=-283.2 kJ

From the above reaction, the heat of reaction for

C (graphite) + O₂ (g) →CO₂(g) will be [CPMT 1988; MP PMT 1989]

-393.7kJ

+393.7kJ

-172.7 kJ

+172.7

Please select an option

Question#180

The molar neutralization heat for KOH and HNO3 as compared to molar neutralization heat of NaOH and HCl
[MP PMT 1989]

Less

more

equal

Depends upon pressure

Please select an option

Question#181

In which of the following neutralisation reactions, the heat of
neutralisation will be highest
[MP PMT 1989, 91; AIIMS 1999]

NH₄OH and CH₃COOH

NH₄OH and HCl

NaOH and CH₃COOH

NaOH and HCl

Please select an option

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Home/Thermochemistry

Heat of reaction

C₂H₄