For a reaction with and

CHEMISTRY · Single correct · A Level · Chemistry · Thermodynamics · Thermodynamics

Problem

For a reaction with

\Delta H^\circ > 0

and

\Delta S^\circ > 0

, which statement best describes how the equilibrium constant

K

changes as temperature is increased? (a) K decreases because the term

T\Delta S^{\circ}

adds to

\Delta H^{\circ}

, so

\Delta G^{\circ}

increases with temperature. (b) K remains less than 1 at all temperatures because both

\Delta H^{\circ}

and

\Delta S^{\circ}

are positive. (c) K increases because the free-energy term

-T\Delta S^{\circ}

becomes more negative at higher temperatures. (d) K decreases because the term

-\dfrac{\Delta H^{\circ}}{RT}

becomes more negative as

T

increases.