HARD

Earn 100

The heat of combustion of glucose is $- 2840 kJ {mol}^{- 1}$ . Find volume of $O_{2}$ gas required for complete combustion at STP if $5.68 kJ$ heat was released on the combustion of glucose.

Important Questions on Chemical Thermodynamics

MEDIUM

Chemistry>Physical Chemistry>Chemical Thermodynamics>Thermochemistry

Lattice enthalpy and enthalpy of solution of

NaCl

are

788 {kJmol}^{- 1}

and

4 k J m o l^{- 1}

, respectively. The hydration enthalpy of

N a C l

is:

MEDIUM

Chemistry>Physical Chemistry>Chemical Thermodynamics>Thermochemistry

The combustion of benzene

(l)

gives

{CO}_{2} (g)

and

H_{2} O (l) .

Given that heat of combustion of benzene at constant volume is

- 3263 .9 kJ {mol}^{- 1}

25 ° C;

the heat of combustion

(in kJ {mol}^{- 1})

of benzene at constant pressure will be

(R = 8 .314 {JK}^{- 1} {mol}^{- 1})

HARD

Chemistry>Physical Chemistry>Chemical Thermodynamics>Thermochemistry

Choose the reaction(s) from the following options, for which the standard enthalpy of reaction is equal to the standard enthalpy of formation.

MEDIUM

Chemistry>Physical Chemistry>Chemical Thermodynamics>Thermochemistry

The elements with the highest and the lowest enthalpy of atomisation respectively, for first row transition elements are:

EASY

Chemistry>Physical Chemistry>Chemical Thermodynamics>Thermochemistry

Identify the INVALID equation.

HARD

Chemistry>Physical Chemistry>Chemical Thermodynamics>Thermochemistry

The enthalpies of formation of

{CO}_{(g)}, {CO}_{2 (g)}

and

N_{2} O_{(g)}

are -110,-393 and

81 kJ {mol}^{- 1}

respectively. If the enthalpy of reaction

(Δ_{r} H)

for

N_{2} O_{4 (g)} + 3 {CO}_{(g)} \to N_{2} O_{(g)} + 3 {CO}_{2 (g)}

- 778 kJ,

the enthalpy of formation of

N_{2} O_{4} (g)

{kJmol}^{- 1}

MEDIUM

Chemistry>Physical Chemistry>Chemical Thermodynamics>Thermochemistry

The heats of combustion of carbon and carbon monoxide are

- 393.5 a n d - 283.5 k J m o l^{- 1},

respectively. The heat of formation

(in kJ)

of carbon monoxide per mole is:

MEDIUM

Chemistry>Physical Chemistry>Chemical Thermodynamics>Thermochemistry

The standard enthalpy of combustion of carbon is

393.5 kJ {mol}^{- 1}

. The amount of heat released when carbon and oxygen gas produce

35.2 g

{CO}_{2}

HARD

Chemistry>Physical Chemistry>Chemical Thermodynamics>Thermochemistry

The standard enthalpies of formation of ${CO}_{2} (g)$ $, H_{2} O (l)$ and glucose (s) at $2 5^{o} C$ are $- 400 kJ / mol$ , $- 300 kJ / mol$ and $- 1300 kJ / mol$ , respectively. The standard enthalpy combustion per gram of glucose at $2 5^{o} C$ is

( ${ΔH}_{f}^{0} = - 1300 kJ {mol}^{- 1}$ for Glucose)

HARD

Chemistry>Physical Chemistry>Chemical Thermodynamics>Thermochemistry

For the reaction

N_{2} + 3 X_{2} \to 2 {NX}_{3}

where

X = F, Cl

(the average bond energies are

F - F = 155 kJ {mol}^{- 1}, N - F = 272 kJ {mol}^{- 1}, Cl - Cl = 242 kJ {mol}^{- 1}, N - Cl = 200 kJ {mol}^{- 1}

and

N \equiv N = 941 kJ {mol}^{- 1}

), the heats of reaction of

{NF}_{3}

and

{NCl}_{3}

kJ {mol}^{- 1},

respectively, are closest to

HARD

Chemistry>Physical Chemistry>Chemical Thermodynamics>Thermochemistry

For one mole of NaCl(s) the lattice enthalpy is

${Na}_{(s)} + \frac{1}{2} {Cl}_{2} (g) \overset{+ 108.4 kJ / mol}{⟶} {Na}_{(s)} + \frac{1}{2} {Cl}_{2} (g) \overset{+ 495.6 kJ / mol}{⟶} {Na}_{(g)}^{+} + \frac{1}{2} {Cl}_{2} (g) \overset{121 kJ / mol}{⟶}$

${Na}_{(g)}^{+} + Cl (g) \overset{- 348.6 kJ / mol}{⟶} {Na}_{(g)}^{+} + {Cl}_{(g)}^{-} \overset{{ΔH}^{0} altice}{⟶} Nacl$ (solid) $\underset{- 411.2 kJ / mol}{\leftarrow} {Na}_{(s)} + \frac{1}{2} {Cl}_{2} (g)$

EASY

Chemistry>Physical Chemistry>Chemical Thermodynamics>Thermochemistry

The heat of combustion of carbon to

C O_{2}

- 393.5 kJ / mol

. The heat released upon the formation of

35.2 g

C O_{2}

from carbon and oxygen gas is

MEDIUM

Chemistry>Physical Chemistry>Chemical Thermodynamics>Thermochemistry

The average $S - F$ bond energy in $kJ {mol}^{- 1}$ of ${SF}_{6}$ is _. (Rounded off to the nearest integer)

[Given : The values of standard enthalpy of formation of ${SF}_{6} (g), S (g)$ and $F (g)$ are $- 1100, 275$ and $80 kJ {mol}^{- 1}$ respectively.]

MEDIUM

Chemistry>Physical Chemistry>Chemical Thermodynamics>Thermochemistry

Enthalpy of combustion of methane and ethane are

- 210 k cal / mol

and

- 368 k cal / mol

respectively. The enthalpy of combustion of decane is

EASY

Chemistry>Physical Chemistry>Chemical Thermodynamics>Thermochemistry

The standard enthalpies of formation of ${Al}_{2} O_{3}$ and $CaO$ are $- 1675 kJ {mol}^{- 1}$ and $- 635 kJ {mol}^{- 1}$ respectively.

For the reaction

$3 CaO + 2 Al \to 3 Ca + {Al}_{2} O_{3}$ the standard reaction enthalpy $Δ_{r} H^{0} =$ ________ $kJ .$

(Round off to the Nearest Integer).

MEDIUM

Chemistry>Physical Chemistry>Chemical Thermodynamics>Thermochemistry

What will be the enthalpy of formation of toluene considering the data given?
Bond energies of

C - C = 79 kcal, C = C = 135 kcal,

C - H = 102 kcal,

heat of atomisation of

C = 156.8 kcal

and heat of atomisation of

H = 49.5 kcal

EASY

Chemistry>Physical Chemistry>Chemical Thermodynamics>Thermochemistry

Given that bond energies of

H - H

and

Cl - Cl

are

430 kJ {mol}^{- 1}

and

240 kJ {mol}^{- 1}

respectively and

{ΔH}_{f}

for

HCl

- 90 kJ {mol}^{- 1}

. The bond energy of

HCl

MEDIUM

Chemistry>Physical Chemistry>Chemical Thermodynamics>Thermochemistry

The standard enthalpy of formation of

{NH}_{3}

- 46.0 kJ / mol

. If bond enthalpy of

H_{2}

- 436 kJ / mol

and that of

N_{2}

- 712 kJ / mol

, the average bond enthalpy of

N - H

bond in

{NH}_{3}

is :

HARD

Chemistry>Physical Chemistry>Chemical Thermodynamics>Thermochemistry

The heat of atomization of methane and ethane are

360 kJ {mol}^{- 1}

and

620 kJ {mol}^{- 1}

, respectively. The longest wavelength of light capable of breaking the

C - C

bond is (Avogadro's number

= 6.023 \times 10^{23}, h = 6.62 \times 10^{- 34} J s

)

EASY

Chemistry>Physical Chemistry>Chemical Thermodynamics>Thermochemistry

The value of

∆ H

for the combustion of

C (s)

- 94.0 kcal

. The heat of formation of

{CO}_{2} (g)

The heat of combustion of glucose is -2840 kJ mol-1. Find volume of O2 gas required for complete combustion at STP if 5.68 kJ heat was released on the combustion of glucose.

Important Questions on Chemical Thermodynamics

Learn and Prepare for any exam you want !

The heat of combustion of glucose is $- 2840 kJ {mol}^{- 1}$ . Find volume of $O_{2}$ gas required for complete combustion at STP if $5.68 kJ$ heat was released on the combustion of glucose.