For a spontaneous reaction at all temperatures,which of the following is correct?

  • A
    Both $\Delta H$ and $\Delta S$ are positive
  • B
    $\Delta H$ is positive and $\Delta S$ is negative
  • C
    $\Delta H$ is negative and $\Delta S$ is positive
  • D
    Both $\Delta H$ and $\Delta S$ are negative

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Similar Questions

Identify the correct statement for the change in Gibbs energy $(\Delta G_{\text{system}})$ for a system at constant temperature and pressure.

The effect of temperature on the spontaneity of reactions is represented as follows:
Condition Details
$A$. $\Delta H: +, \Delta S: -$ $T$: any $T$,Spontaneity: Non-spontaneous
$B$. $\Delta H: +, \Delta S: +$ $T$: low $T$,Spontaneity: Non-spontaneous
$C$. $\Delta H: -, \Delta S: -$ $T$: low $T$,Spontaneity: Spontaneous
$D$. $\Delta H: -, \Delta S: +$ $T$: any $T$,Spontaneity: Spontaneous

Which of the above conditions are correctly matched?

For the reaction $PCl_5 \to PCl_3 + Cl_2$,$\Delta H = 75 \ kJ \ mol^{-1}$ and $\Delta S = 120 \ J \ K^{-1} \ mol^{-1}$. At which temperature will the reaction be spontaneous? (in $K$)

For the melting of $3 \ moles$ of water at $0 \, ^\circ C$,the $\Delta G^o$ is:

For the reaction $CaCO_3(s) \rightarrow CaO(s) + CO_2(g)$ at $298 \ K$ and $1 \ atm$ pressure,the values of $\Delta H^o$ and $\Delta S^o$ are $+179.1 \ kJ \ mol^{-1}$ and $+160.2 \ J \ K^{-1} \ mol^{-1}$ respectively. Assuming that $\Delta H^o$ and $\Delta S^o$ do not change with temperature,at what temperature (in $K$) will the process become spontaneous?

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