Given

(i)  C (graphite) + O₂(g) $$ \to $$ CO₂(g); $$\Delta $$rH$$^\Theta $$ = x kJ mol^$$-$$1

(ii)  C(graphite) + $${1 \over 2}$$O₂(g) $$ \to $$ CO(g); $$\Delta $$rH$$^\Theta $$ = y kJ mol^$$-$$1

(iii)  CO(g) + $${1 \over 2}$$ O₂(g) $$ \to $$ CO₂(g); $$\Delta $$rH$$^\Theta $$ = z kJ mol^$$-$$1

Based on the above thermochemical equations, find out which one of the following algebraic relationships is correct?

The combination of plots which does not represent isothermal expansion of an ideal gas is –

For diatomic ideal gas in a closed system, which of the following plots does not correctly describe the relation between various thermodynamic quantities?

The reaction, MgO(s) + C(s) $$ \to $$ Mg(s) + CO(g), for which $$\Delta $$_rH^o + 491.1 kJ mol^–1 and $$\Delta $$_rS^o = 198.0 JK^–1 mol^–1, is not feasible at 298 K. Temperature above which reaciton will be feasible is :