Given

(i)   2Fe₂O₃(s) $$ \to $$ 4Fe(s) + 3O₂(g);

$$\Delta $$_rG^o = + 1487.0 kJ mol^-1

(ii)   2CO(g) + O₂(g) $$ \to $$ 2CO₂(g);

$$\Delta $$_rG^o = $$-$$ 514.4 kJ mol^-1

Free energy change, $$\Delta $$_rG^o for the reaction

2Fe₂O₃(s) + 6CO(g) $$ \to $$ 4Fe(s) + 6CO₂(g) will be :

$$\Delta $$_fG^o at 500 K for substance 'S' in liquid state and gaseous state are +100.7 kcl mol-¹ and +103 kcal mol^-1, respectively. Vapour pressure of liquid 'S' at 500 K is approximately equal to : ( R = 2 cal K^-1 mol^-1 )

Following four solutions are prepared by mixing different volumes of NaOH and HCl of different concentrations, pH of which one of them will be equal to 1 ?

Biochemical Oxygen Demand (BOD) value can be a measure of water pollution caused by the organic matter. Which of the following statements is correct ?