If for and are 45.7, 49.0, 48.2, 50.24, 57.24 and 72.77 cal respectively and N _2 + 1…

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

Problem

S^\circ

for

\text{N}_2, \text{O}_2, \text{N}_2\text{O}, \text{NO}, \text{NO}_2

and

\text{N}_2\text{O}_4

are 45.7, 49.0, 48.2, 50.24, 57.24 and 72.77 cal respectively and

\text{N}_2 + \frac{1}{2}\text{O}_2 \rightleftharpoons \text{N}_2\text{O}; \quad \Delta H^\circ = 19.49 \text{ kcal at } 300 \text{ K}

\frac{1}{2}\text{N}_2 + \frac{1}{2}\text{O}_2 \rightleftharpoons \text{NO}; \quad \Delta H^\circ = 21.60 \text{ kcal at } 300 \text{ K}

\frac{1}{2}\text{N}_2 + \text{O}_2 \rightleftharpoons \text{NO}_2; \quad \Delta H^\circ = 8.09 \text{ kcal at } 300 \text{ K}

\text{N}_2 + 2\text{O}_2 \rightleftharpoons \text{N}_2\text{O}_4; \quad \Delta H^\circ = 2.19 \text{ kcal at } 300 \text{ K}

For which

\Delta G^\circ

is more +ve : (1)

\text{N}_2\text{O}

(2)

\text{NO}

(3)

\text{NO}_2

(4)

\text{N}_2\text{O}_4