Molar mass of the salt from NaBr, \(NaNO_3\)β, KI and \(CaF_2\)β which does not evolve coloured vapours on heating with concentrated \(H_2βSO_4\)β is _____ g \(mol^{β1}\). (Molar mass in g molβ1: Na : 23, N : 14, K : 39, O : 16, Br : 80, I : 127, F : 19, Ca : 40)