The mass of a non-volatile, non-electrolyte solute (molar mass = 50 g mol^-1 ) needed to be dissolved in 114 g octane to reduce its vapour pressure to 75%, is :

The incorrect statement is :

At 320 K, a gas A₂ is 20% dissociated to A(g). The standard free energy change at 320 K and 1 atm in J mol^-1 is approximately : (R = 8.314 JK^-1 mol^-1; ln2 = 0.693; ln 3 = 1.098)

Which of the following statements is false ?