A salt QCl of a certain metal Q is electrolyzed to its elements. 40 g of metal Q is formed at an electrode. The volume of Cl2 formed at the other electrode at 1 atm pressure and 298 K is _______ litres. (rounded off to one decimal place) [Given: The gas constant π = 0.082 L atm molβ1 Kβ1 , the molar mass of Q is 40 g molβ1 and Cl2 is assumed to be an ideal gas]