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Calculate the free energy change of the reaction $straight C left parenthesis graphite right parenthesis space plus space straight O subscript 2 left parenthesis straight g right parenthesis space space space rightwards arrow space space space CO subscript 2 left parenthesis straight g right parenthesis$
$left parenthesis Given space increment straight H space equals space minus 300 space kJ space mol to the power of negative 1 end exponent semicolon space space increment straight S space equals space 3 space JK to the power of negative 1 end exponent space mol to the power of negative 1 end exponent space at space 300 space straight K right parenthesis.$

105 Views

272.

For the reaction:
$straight N subscript 2 left parenthesis straight g right parenthesis space plus space 3 straight H subscript 2 left parenthesis straight g right parenthesis space space rightwards arrow space space 2 NH subscript 3 left parenthesis straight g right parenthesis comma$
$increment straight H equals negative 95.4 space kJ space and space increment straight S space equals space minus 198.3 space kJ divided by straight K.$

Calculate the temperature at which it attains equilibrium.

97 Views

Long Answer Type

273.

At what temperature, reduction of lead oxide to lead by carbon

becomes spontaneous? For this reason are 108.4 kJ mol^-1 and 190.0 JK^-1 mol^-1 respectively.

222 Views

274.

For the reaction at 298 K
$2 straight A plus straight B rightwards arrow straight C$
$increment straight H space equals space 400 space kJ space mol to the power of negative 1 end exponent space and space increment straight S space equals space 0.2 space kJ space straight K to the power of negative 1 end exponent mol to the power of negative 1 end exponent.$

At what temperature will the reaction become spontaneous considering $increment straight H space and space increment straight S$ to be constant over the temperature range?

119 Views

Short Answer Type

275.

For the reaction
$2 straight A left parenthesis straight g right parenthesis space plus space straight B left parenthesis straight g right parenthesis space space space rightwards arrow space space space 2 straight D left parenthesis straight g right parenthesis increment straight U to the power of 0 space equals space minus 10.5 space kJ space and space increment straight S to the power of 0 space equals space minus 44.1 space JK to the power of negative 1 end exponent.$

Calculate $increment straight G to the power of 0$ for the reaction and predict whether the reaction may occur spontaneously.

115 Views

Long Answer Type

276.

For the reaction
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$increment straight H space equals space 30.56 space kJ space mol to the power of negative 1 end exponent space and space increment straight S space equals space 0.06 space kJK to the power of negative 1 end exponent space mol to the power of negative 1 end exponent left parenthesis at space 1 space atm right parenthesis$ , calculate the temperature at which $increment straight G$ is equal to zero. Also predict the direction of the reaction at:
(i) temperature
(ii) below this temperature

93 Views

Short Answer Type

277.

For the melting of ice at $25 degree straight C comma$
$straight H subscript 2 straight O left parenthesis straight s right parenthesis space space space rightwards harpoon over leftwards harpoon space space straight H subscript 2 straight O left parenthesis l right parenthesis comma$
the enthalpy of fusion is $6.97 space kJ space mol to the power of negative 1 end exponent$ and entropy of fusion is 25.4 $JK to the power of negative 1 end exponent mol to the power of negative 1 end exponent.$ Calculate the free energy change and predict whether the melting of ice is spontaneous or not at this temperature.

113 Views

Long Answer Type

278.
What do you understand by:
(i) Standard free energy change (∆_rG⁰)
(ii) Standard free energy of formation (∆_fG⁰).

(i) Standard free energy change (∆G⁰): It is defined as ‘the free energy change for a process at 298K in which the reactants in their standard states are converted into the products in their standard states’. Thus,

The value of ∆G⁰ for a reaction can be derived from the standard free energies of formation (∆_fG⁰).

(ii) Standard free energy of formation (∆_fG⁰) of a compound is defined as ‘the change in free energy when 1 mole of a compound is formed from its constituent elements in their standard states”. Thus,

= [Sum of the standard free energies of formation of products] - [Sum of the standard free energies of formation of reactants]
It may be pointed here that ‘the standard free energy of formation of an element in its standard state is zero’.

115 Views

Short Answer Type

279.

Calculate the standard free energy change for the reaction
$4 NH subscript 3 left parenthesis straight g right parenthesis space plus space 5 straight O subscript 2 space space space rightwards arrow space space space 4 NO left parenthesis straight g right parenthesis space plus space 6 straight H subscript 2 straight O left parenthesis straight l right parenthesis$

Given that the standard free energies of formation $increment subscript straight f straight G to the power of 0$ for $NH subscript 3 left parenthesis straight g right parenthesis comma space space NO left parenthesis straight g right parenthesis space and space straight H subscript 2 straight O left parenthesis straight l right parenthesis$ are -16.8, +86.7 and -237.2 kJ mol^-1 respectively. Predict the feasibility of the above reaction at the standard state.