369420
Assertion : Many endothermic reactions that are not spontaneous at room temperature become spontaneous at high temperature Reason : Entropy of the system decreases with inerease in temperature.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but Reason is correct.
Explanation:
Assertion is true but reason is false. The factor \({\text{T}}\Delta {\text{S}}\) increase with increase in temperature. When \(\mathrm{T} \Delta \mathrm{S}\) is more than \(\Delta \mathrm{H}\), \(\Delta \mathrm{G}\) will become -ve and process become spontaneous and entropy is directly propotional to temperature. So, option (3) is correct.
CHXI06:THERMODYNAMICS
369421
Pick out the wrong statements
1 The standard free energy of formation of all elements is zero
2 A process accompanied by decrease in entropy is spontaneous under certain conditions
3 The entropy of a perfectly crystalline substance at absolute zero is zero
4 A process that leads to increase in free energy will be spontaneous
Explanation:
A process is spontaneous only when there is decrease in the value of free energy, i.e., \(\mathrm{\Delta \mathrm{G}}\) is \(\mathrm{-\mathrm{ve}}\)
CHXI06:THERMODYNAMICS
369422
Considering the reaction: \(\mathrm{\mathrm{C}_{(\mathrm{s})}+\mathrm{O}_{2(\mathrm{~g})} \rightarrow \mathrm{CO}_{2(\mathrm{~g})}+393.5 \mathrm{~kJ}}\) the signs of \(\mathrm{\Delta \mathrm{H}, \Delta \mathrm{S}}\) and \(\mathrm{\Delta \mathrm{G}}\) respectively are
1 \({\rm{ + , - , - }}\)
2 \({\rm{ - , + , + }}\)
3 \({\rm{ - , - , - }}\)
4 \({\rm{ - , + , - }}\)
Explanation:
\(\mathrm{\mathrm{C}_{(\mathrm{s})}+\mathrm{O}_{2(\mathrm{~g})} \rightarrow \mathrm{CO}_{2(\mathrm{~g})}+393.5 \mathrm{~kJ}}\) \(\rm{\Delta \mathrm{H}=-, \Delta \mathrm{S}=+, \Delta \mathrm{G}=-}\) Its an exothermic reaction. Therefore \(\mathrm{\Delta \mathrm{H}=-\mathrm{ve}}\) as energy is released during an exothermic reaction. As its a spontaneous reaction, \(\mathrm{\Delta \mathrm{G}=-\mathrm{ve}}\). Also entropy or randomness increases while moving from LHS to RHS. Therefore \(\mathrm{\Delta \mathrm{S}=+\mathrm{ve}}\).
CHXI06:THERMODYNAMICS
369424
Conversion of oxygen into ozone is non spontaneous at
1 all temperatures
2 high temperature
3 room temperature
4 low temperature.
Explanation:
\(\mathrm{3 \mathrm{O}_{2(\mathrm{~g})} \rightleftharpoons 2 \mathrm{O}_{3(\mathrm{~g})} ; \Delta \mathrm{H}=+\mathrm{ve} ; \Delta \mathrm{S}=-\mathrm{ve}}\) Equation, \(\mathrm{\Delta \mathrm{G}=\Delta \mathrm{H}-\mathrm{T} \Delta \mathrm{S}=+\mathrm{ve}-(-\mathrm{ve})}\) \(\mathrm{\Delta \mathrm{G}=+\mathrm{ve}}\); Non - spontaneous at all temperatures.
369420
Assertion : Many endothermic reactions that are not spontaneous at room temperature become spontaneous at high temperature Reason : Entropy of the system decreases with inerease in temperature.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but Reason is correct.
Explanation:
Assertion is true but reason is false. The factor \({\text{T}}\Delta {\text{S}}\) increase with increase in temperature. When \(\mathrm{T} \Delta \mathrm{S}\) is more than \(\Delta \mathrm{H}\), \(\Delta \mathrm{G}\) will become -ve and process become spontaneous and entropy is directly propotional to temperature. So, option (3) is correct.
CHXI06:THERMODYNAMICS
369421
Pick out the wrong statements
1 The standard free energy of formation of all elements is zero
2 A process accompanied by decrease in entropy is spontaneous under certain conditions
3 The entropy of a perfectly crystalline substance at absolute zero is zero
4 A process that leads to increase in free energy will be spontaneous
Explanation:
A process is spontaneous only when there is decrease in the value of free energy, i.e., \(\mathrm{\Delta \mathrm{G}}\) is \(\mathrm{-\mathrm{ve}}\)
CHXI06:THERMODYNAMICS
369422
Considering the reaction: \(\mathrm{\mathrm{C}_{(\mathrm{s})}+\mathrm{O}_{2(\mathrm{~g})} \rightarrow \mathrm{CO}_{2(\mathrm{~g})}+393.5 \mathrm{~kJ}}\) the signs of \(\mathrm{\Delta \mathrm{H}, \Delta \mathrm{S}}\) and \(\mathrm{\Delta \mathrm{G}}\) respectively are
1 \({\rm{ + , - , - }}\)
2 \({\rm{ - , + , + }}\)
3 \({\rm{ - , - , - }}\)
4 \({\rm{ - , + , - }}\)
Explanation:
\(\mathrm{\mathrm{C}_{(\mathrm{s})}+\mathrm{O}_{2(\mathrm{~g})} \rightarrow \mathrm{CO}_{2(\mathrm{~g})}+393.5 \mathrm{~kJ}}\) \(\rm{\Delta \mathrm{H}=-, \Delta \mathrm{S}=+, \Delta \mathrm{G}=-}\) Its an exothermic reaction. Therefore \(\mathrm{\Delta \mathrm{H}=-\mathrm{ve}}\) as energy is released during an exothermic reaction. As its a spontaneous reaction, \(\mathrm{\Delta \mathrm{G}=-\mathrm{ve}}\). Also entropy or randomness increases while moving from LHS to RHS. Therefore \(\mathrm{\Delta \mathrm{S}=+\mathrm{ve}}\).
CHXI06:THERMODYNAMICS
369424
Conversion of oxygen into ozone is non spontaneous at
1 all temperatures
2 high temperature
3 room temperature
4 low temperature.
Explanation:
\(\mathrm{3 \mathrm{O}_{2(\mathrm{~g})} \rightleftharpoons 2 \mathrm{O}_{3(\mathrm{~g})} ; \Delta \mathrm{H}=+\mathrm{ve} ; \Delta \mathrm{S}=-\mathrm{ve}}\) Equation, \(\mathrm{\Delta \mathrm{G}=\Delta \mathrm{H}-\mathrm{T} \Delta \mathrm{S}=+\mathrm{ve}-(-\mathrm{ve})}\) \(\mathrm{\Delta \mathrm{G}=+\mathrm{ve}}\); Non - spontaneous at all temperatures.
369420
Assertion : Many endothermic reactions that are not spontaneous at room temperature become spontaneous at high temperature Reason : Entropy of the system decreases with inerease in temperature.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but Reason is correct.
Explanation:
Assertion is true but reason is false. The factor \({\text{T}}\Delta {\text{S}}\) increase with increase in temperature. When \(\mathrm{T} \Delta \mathrm{S}\) is more than \(\Delta \mathrm{H}\), \(\Delta \mathrm{G}\) will become -ve and process become spontaneous and entropy is directly propotional to temperature. So, option (3) is correct.
CHXI06:THERMODYNAMICS
369421
Pick out the wrong statements
1 The standard free energy of formation of all elements is zero
2 A process accompanied by decrease in entropy is spontaneous under certain conditions
3 The entropy of a perfectly crystalline substance at absolute zero is zero
4 A process that leads to increase in free energy will be spontaneous
Explanation:
A process is spontaneous only when there is decrease in the value of free energy, i.e., \(\mathrm{\Delta \mathrm{G}}\) is \(\mathrm{-\mathrm{ve}}\)
CHXI06:THERMODYNAMICS
369422
Considering the reaction: \(\mathrm{\mathrm{C}_{(\mathrm{s})}+\mathrm{O}_{2(\mathrm{~g})} \rightarrow \mathrm{CO}_{2(\mathrm{~g})}+393.5 \mathrm{~kJ}}\) the signs of \(\mathrm{\Delta \mathrm{H}, \Delta \mathrm{S}}\) and \(\mathrm{\Delta \mathrm{G}}\) respectively are
1 \({\rm{ + , - , - }}\)
2 \({\rm{ - , + , + }}\)
3 \({\rm{ - , - , - }}\)
4 \({\rm{ - , + , - }}\)
Explanation:
\(\mathrm{\mathrm{C}_{(\mathrm{s})}+\mathrm{O}_{2(\mathrm{~g})} \rightarrow \mathrm{CO}_{2(\mathrm{~g})}+393.5 \mathrm{~kJ}}\) \(\rm{\Delta \mathrm{H}=-, \Delta \mathrm{S}=+, \Delta \mathrm{G}=-}\) Its an exothermic reaction. Therefore \(\mathrm{\Delta \mathrm{H}=-\mathrm{ve}}\) as energy is released during an exothermic reaction. As its a spontaneous reaction, \(\mathrm{\Delta \mathrm{G}=-\mathrm{ve}}\). Also entropy or randomness increases while moving from LHS to RHS. Therefore \(\mathrm{\Delta \mathrm{S}=+\mathrm{ve}}\).
CHXI06:THERMODYNAMICS
369424
Conversion of oxygen into ozone is non spontaneous at
1 all temperatures
2 high temperature
3 room temperature
4 low temperature.
Explanation:
\(\mathrm{3 \mathrm{O}_{2(\mathrm{~g})} \rightleftharpoons 2 \mathrm{O}_{3(\mathrm{~g})} ; \Delta \mathrm{H}=+\mathrm{ve} ; \Delta \mathrm{S}=-\mathrm{ve}}\) Equation, \(\mathrm{\Delta \mathrm{G}=\Delta \mathrm{H}-\mathrm{T} \Delta \mathrm{S}=+\mathrm{ve}-(-\mathrm{ve})}\) \(\mathrm{\Delta \mathrm{G}=+\mathrm{ve}}\); Non - spontaneous at all temperatures.
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CHXI06:THERMODYNAMICS
369420
Assertion : Many endothermic reactions that are not spontaneous at room temperature become spontaneous at high temperature Reason : Entropy of the system decreases with inerease in temperature.
1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.
2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.
3 Assertion is correct but Reason is incorrect.
4 Assertion is incorrect but Reason is correct.
Explanation:
Assertion is true but reason is false. The factor \({\text{T}}\Delta {\text{S}}\) increase with increase in temperature. When \(\mathrm{T} \Delta \mathrm{S}\) is more than \(\Delta \mathrm{H}\), \(\Delta \mathrm{G}\) will become -ve and process become spontaneous and entropy is directly propotional to temperature. So, option (3) is correct.
CHXI06:THERMODYNAMICS
369421
Pick out the wrong statements
1 The standard free energy of formation of all elements is zero
2 A process accompanied by decrease in entropy is spontaneous under certain conditions
3 The entropy of a perfectly crystalline substance at absolute zero is zero
4 A process that leads to increase in free energy will be spontaneous
Explanation:
A process is spontaneous only when there is decrease in the value of free energy, i.e., \(\mathrm{\Delta \mathrm{G}}\) is \(\mathrm{-\mathrm{ve}}\)
CHXI06:THERMODYNAMICS
369422
Considering the reaction: \(\mathrm{\mathrm{C}_{(\mathrm{s})}+\mathrm{O}_{2(\mathrm{~g})} \rightarrow \mathrm{CO}_{2(\mathrm{~g})}+393.5 \mathrm{~kJ}}\) the signs of \(\mathrm{\Delta \mathrm{H}, \Delta \mathrm{S}}\) and \(\mathrm{\Delta \mathrm{G}}\) respectively are
1 \({\rm{ + , - , - }}\)
2 \({\rm{ - , + , + }}\)
3 \({\rm{ - , - , - }}\)
4 \({\rm{ - , + , - }}\)
Explanation:
\(\mathrm{\mathrm{C}_{(\mathrm{s})}+\mathrm{O}_{2(\mathrm{~g})} \rightarrow \mathrm{CO}_{2(\mathrm{~g})}+393.5 \mathrm{~kJ}}\) \(\rm{\Delta \mathrm{H}=-, \Delta \mathrm{S}=+, \Delta \mathrm{G}=-}\) Its an exothermic reaction. Therefore \(\mathrm{\Delta \mathrm{H}=-\mathrm{ve}}\) as energy is released during an exothermic reaction. As its a spontaneous reaction, \(\mathrm{\Delta \mathrm{G}=-\mathrm{ve}}\). Also entropy or randomness increases while moving from LHS to RHS. Therefore \(\mathrm{\Delta \mathrm{S}=+\mathrm{ve}}\).
CHXI06:THERMODYNAMICS
369424
Conversion of oxygen into ozone is non spontaneous at
1 all temperatures
2 high temperature
3 room temperature
4 low temperature.
Explanation:
\(\mathrm{3 \mathrm{O}_{2(\mathrm{~g})} \rightleftharpoons 2 \mathrm{O}_{3(\mathrm{~g})} ; \Delta \mathrm{H}=+\mathrm{ve} ; \Delta \mathrm{S}=-\mathrm{ve}}\) Equation, \(\mathrm{\Delta \mathrm{G}=\Delta \mathrm{H}-\mathrm{T} \Delta \mathrm{S}=+\mathrm{ve}-(-\mathrm{ve})}\) \(\mathrm{\Delta \mathrm{G}=+\mathrm{ve}}\); Non - spontaneous at all temperatures.
