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 𝑅 = 0.082 L atm mol−1 K−1 , the molar mass of Q is 40 g mol−1 and Cl2 is assumed to be an ideal gas]