Question

The values of AH and AS for the reaction,
(graphite) + CO2(g) → 2CO(g)
are 170 kJ and 170 JK- respectively. This reaction
will be spontaneous at [AIPMT (Prelims)-2009]
(1) 910 K
(2) 1110 K
(3) 510 K
(4) 710 K​

Answer 1

The reaction  will be spontaneous at 1110 K

Explanation:

$\Delta G$= +ve, reaction is non spontaneous

$\Delta G$= -ve, reaction is spontaneous

$\Delta G$= 0, reaction is in equilibrium

According to Gibb's equation:

$\Delta G=\Delta H-T\Delta S$

$\Delta G$ = Gibbs free energy  

$\Delta H$ = enthalpy change  = 170 kJ = 170000 J   (1kJ=1000J)

$\Delta S$ = entropy change  = 170 J/K

T = temperature in Kelvin

Putting in the values we get:

$\Delta G=170000-T\times (170)$

For reaction to be spontaneous : $\Delta G$= -ve,

Thus $T\times (170)>170000$

$T>\frac{170000}{170}=1000K$

Learn More

Spontaneity of reaction:

https://brainly.com/question/9748006

Application of Gibb's equation:

https://brainly.com/question/12893688